21153125172 has 24 divisors (see below), whose sum is σ = 49359678592. Its totient is φ = 7050700800.

The previous prime is 21153125111. The next prime is 21153125197. The reversal of 21153125172 is 27152135112.

It is a congruent number.

It is an unprimeable number.

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, 398772 + ... + 448692.

Almost surely, 2^21153125172 is an apocalyptic number.

It is an amenable number.

21153125172 is an abundant number, since it is smaller than the sum of its proper divisors (28206553420).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21153125172 is a wasteful number, since it uses less digits than its factorization.

21153125172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85239 (or 85237 counting only the distinct ones).

The product of its digits is 4200, while the sum is 30.

The spelling of 21153125172 in words is "twenty-one billion, one hundred fifty-three million, one hundred twenty-five thousand, one hundred seventy-two".