21604552331 has 8 divisors (see below), whose sum is σ = 21857829840. Its totient is φ = 21351508992.

The previous prime is 21604552247. The next prime is 21604552373. The reversal of 21604552331 is 13325540612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21604552331 - 2²⁶ = 21537443467 is a prime.

It is a super-2 number, since 2×21604552331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21604552231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130616 + ... + 245498.

It is an arithmetic number, because the mean of its divisors is an integer number (2732228730).

Almost surely, 2^21604552331 is an apocalyptic number.

21604552331 is a deficient number, since it is larger than the sum of its proper divisors (253277509).

21604552331 is a wasteful number, since it uses less digits than its factorization.

21604552331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117085.

The product of its (nonzero) digits is 21600, while the sum is 32.

The spelling of 21604552331 in words is "twenty-one billion, six hundred four million, five hundred fifty-two thousand, three hundred thirty-one".