213867440640 has 640 divisors, whose sum is σ = 889458071040. Its totient is φ = 47687270400.

The previous prime is 213867440629. The next prime is 213867440641. The reversal of 213867440640 is 46044768312.

213867440640 is a `hidden beast` number, since 2 + 138 + 6 + 74 + 406 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (213867440641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 19832050 + ... + 19842830.

It is an arithmetic number, because the mean of its divisors is an integer number (1389778236).

Almost surely, 2^213867440640 is an apocalyptic number.

213867440640 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 213867440640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (444729035520).

213867440640 is an abundant number, since it is smaller than the sum of its proper divisors (675590630400).

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

213867440640 is a wasteful number, since it uses less digits than its factorization.

213867440640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10861 (or 10839 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 45.

The spelling of 213867440640 in words is "two hundred thirteen billion, eight hundred sixty-seven million, four hundred forty thousand, six hundred forty".