21252039521 has 8 divisors (see below), whose sum is σ = 21989275200. Its totient is φ = 20515097680.

The previous prime is 21252039509. The next prime is 21252039559. The reversal of 21252039521 is 12593025212.

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 21252039521 - 2¹⁴ = 21252023137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21252039121) 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 7 ways as a sum of consecutive naturals, for example, 79100 + ... + 220818.

It is an arithmetic number, because the mean of its divisors is an integer number (2748659400).

Almost surely, 2^21252039521 is an apocalyptic number.

It is an amenable number.

21252039521 is a deficient number, since it is larger than the sum of its proper divisors (737235679).

21252039521 is a wasteful number, since it uses less digits than its factorization.

21252039521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146919.

The product of its (nonzero) digits is 10800, while the sum is 32.

The spelling of 21252039521 in words is "twenty-one billion, two hundred fifty-two million, thirty-nine thousand, five hundred twenty-one".