21115371724 has 12 divisors (see below), whose sum is σ = 36955946104. Its totient is φ = 10556529984.

The previous prime is 21115371689. The next prime is 21115371733. The reversal of 21115371724 is 42717351112.

It is a self number, because there is not a number n which added to its sum of digits gives 21115371724.

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, 247197 + ... + 321460.

Almost surely, 2^21115371724 is an apocalyptic number.

It is an amenable number.

21115371724 is a deficient number, since it is larger than the sum of its proper divisors (15840574380).

21115371724 is a wasteful number, since it uses less digits than its factorization.

21115371724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 577944 (or 577942 counting only the distinct ones).

The product of its digits is 11760, while the sum is 34.

The spelling of 21115371724 in words is "twenty-one billion, one hundred fifteen million, three hundred seventy-one thousand, seven hundred twenty-four".