221765040 has 200 divisors, whose sum is σ = 880434720. Its totient is φ = 50678784.

The previous prime is 221765039. The next prime is 221765101. The reversal of 221765040 is 40567122.

221765040 is a `hidden beast` number, since 2 + 2 + 1 + 7 + 650 + 4 + 0 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 221764995 and 221765013.

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 42916 + ... + 47804.

Almost surely, 2^221765040 is an apocalyptic number.

221765040 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 221765040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (440217360).

221765040 is an abundant number, since it is smaller than the sum of its proper divisors (658669680).

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

221765040 is a wasteful number, since it uses less digits than its factorization.

221765040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4921 (or 4906 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 221765040 is about 14891.7775970500. Note that the first 3 decimals coincide. The cubic root of 221765040 is about 605.2912014811.

The spelling of 221765040 in words is "two hundred twenty-one million, seven hundred sixty-five thousand, forty".