21515032325 has 12 divisors (see below), whose sum is σ = 26755534560. Its totient is φ = 17162416560.

The previous prime is 21515032321. The next prime is 21515032339. The reversal of 21515032325 is 52323051512.

It is not a de Polignac number, because 21515032325 - 2² = 21515032321 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515032321) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1231385 + ... + 1248734.

It is an arithmetic number, because the mean of its divisors is an integer number (2229627880).

Almost surely, 2^21515032325 is an apocalyptic number.

21515032325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21515032325 is a deficient number, since it is larger than the sum of its proper divisors (5240502235).

21515032325 is a wasteful number, since it uses less digits than its factorization.

21515032325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2480476 (or 2480471 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 29.

Adding to 21515032325 its reverse (52323051512), we get a palindrome (73838083837).

The spelling of 21515032325 in words is "twenty-one billion, five hundred fifteen million, thirty-two thousand, three hundred twenty-five".