21131521052 has 24 divisors (see below), whose sum is σ = 37193318400. Its totient is φ = 10504937520.

The previous prime is 21131521049. The next prime is 21131521063. The reversal of 21131521052 is 25012513112.

It is a super-2 number, since 2×21131521052² (a number of 21 digits) contains 22 as substring.

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, 1161893 + ... + 1179939.

It is an arithmetic number, because the mean of its divisors is an integer number (1549721600).

Almost surely, 2^21131521052 is an apocalyptic number.

It is an amenable number.

21131521052 is a deficient number, since it is larger than the sum of its proper divisors (16061797348).

21131521052 is a wasteful number, since it uses less digits than its factorization.

21131521052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19721 (or 19719 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

The spelling of 21131521052 in words is "twenty-one billion, one hundred thirty-one million, five hundred twenty-one thousand, fifty-two".