21252039515 has 8 divisors (see below), whose sum is σ = 29145654240. Its totient is φ = 14572827072.

The previous prime is 21252039509. The next prime is 21252039559. The reversal of 21252039515 is 51593025212.

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 21252039515 - 2⁴ = 21252039499 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35), and also a Moran number because the ratio is a prime number: 607201129 = 21252039515 / (2 + 1 + 2 + 5 + 2 + 0 + 3 + 9 + 5 + 1 + 5).

It is an unprimeable number.

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, 303600530 + ... + 303600599.

It is an arithmetic number, because the mean of its divisors is an integer number (3643206780).

Almost surely, 2^21252039515 is an apocalyptic number.

21252039515 is a deficient number, since it is larger than the sum of its proper divisors (7893614725).

21252039515 is an equidigital number, since it uses as much as digits as its factorization.

21252039515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607201141.

The product of its (nonzero) digits is 27000, while the sum is 35.

The spelling of 21252039515 in words is "twenty-one billion, two hundred fifty-two million, thirty-nine thousand, five hundred fifteen".