21125717524 has 24 divisors (see below), whose sum is σ = 37161948096. Its totient is φ = 10508064000.

The previous prime is 21125717491. The next prime is 21125717533. The reversal of 21125717524 is 42571752112.

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, 2562489 + ... + 2570719.

It is an arithmetic number, because the mean of its divisors is an integer number (1548414504).

Almost surely, 2^21125717524 is an apocalyptic number.

It is an amenable number.

21125717524 is a deficient number, since it is larger than the sum of its proper divisors (16036230572).

21125717524 is a wasteful number, since it uses less digits than its factorization.

21125717524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11487 (or 11485 counting only the distinct ones).

The product of its digits is 39200, while the sum is 37.

The spelling of 21125717524 in words is "twenty-one billion, one hundred twenty-five million, seven hundred seventeen thousand, five hundred twenty-four".