213665040 has 240 divisors, whose sum is σ = 771825600. Its totient is φ = 54867456.

The previous prime is 213665017. The next prime is 213665041. The reversal of 213665040 is 40566312.

213665040 is a `hidden beast` number, since 2 + 1 + 3 + 6 + 650 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a zygodrome in base 6.

It is a junction number, because it is equal to n+sod(n) for n = 213664995 and 213665013.

It is not an unprimeable number, because it can be changed into a prime (213665041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 563571 + ... + 563949.

It is an arithmetic number, because the mean of its divisors is an integer number (3215940).

Almost surely, 2^213665040 is an apocalyptic number.

213665040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213665040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (385912800).

213665040 is an abundant number, since it is smaller than the sum of its proper divisors (558160560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

213665040 is a wasteful number, since it uses less digits than its factorization.

213665040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 213665040 is about 14617.2856577410. The cubic root of 213665040 is about 597.8301624677.

It can be divided in two parts, 2136 and 65040, that added together give a palindrome (67176).

The spelling of 213665040 in words is "two hundred thirteen million, six hundred sixty-five thousand, forty".