21525564355 has 8 divisors (see below), whose sum is σ = 25831465632. Its totient is φ = 17219925888.

The previous prime is 21525564343. The next prime is 21525564371. The reversal of 21525564355 is 55346552512.

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 21525564355 - 2¹⁷ = 21525433283 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 277099 + ... + 346171.

It is an arithmetic number, because the mean of its divisors is an integer number (3228933204).

Almost surely, 2^21525564355 is an apocalyptic number.

21525564355 is a deficient number, since it is larger than the sum of its proper divisors (4305901277).

21525564355 is an equidigital number, since it uses as much as digits as its factorization.

21525564355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131405.

The product of its digits is 900000, while the sum is 43.

The spelling of 21525564355 in words is "twenty-one billion, five hundred twenty-five million, five hundred sixty-four thousand, three hundred fifty-five".