21072988525 has 6 divisors (see below), whose sum is σ = 26130505802. Its totient is φ = 16858390800.

The previous prime is 21072988511. The next prime is 21072988577. The reversal of 21072988525 is 52588927012.

It can be written as a sum of positive squares in 3 ways, for example, as 313077636 + 20759910889 = 17694^2 + 144083^2 .

It is not a de Polignac number, because 21072988525 - 2¹¹ = 21072986477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 421459746 + ... + 421459795.

Almost surely, 2^21072988525 is an apocalyptic number.

21072988525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21072988525 is a deficient number, since it is larger than the sum of its proper divisors (5057517277).

21072988525 is an equidigital number, since it uses as much as digits as its factorization.

21072988525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842919551 (or 842919546 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 49.

The spelling of 21072988525 in words is "twenty-one billion, seventy-two million, nine hundred eighty-eight thousand, five hundred twenty-five".