21112515124 has 12 divisors (see below), whose sum is σ = 37011838500. Its totient is φ = 10537704128.

The previous prime is 21112515107. The next prime is 21112515139. The reversal of 21112515124 is 42151521112.

It can be written as a sum of positive squares in 2 ways, for example, as 8040708900 + 13071806224 = 89670^2 + 114332^2 .

It is a super-2 number, since 2×21112515124² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4635799 + ... + 4640350.

It is an arithmetic number, because the mean of its divisors is an integer number (3084319875).

Almost surely, 2^21112515124 is an apocalyptic number.

It is an amenable number.

21112515124 is a deficient number, since it is larger than the sum of its proper divisors (15899323376).

21112515124 is a wasteful number, since it uses less digits than its factorization.

21112515124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9276722 (or 9276720 counting only the distinct ones).

The product of its digits is 800, while the sum is 25.

The spelling of 21112515124 in words is "twenty-one billion, one hundred twelve million, five hundred fifteen thousand, one hundred twenty-four".