21124478136 has 16 divisors (see below), whose sum is σ = 52811195400. Its totient is φ = 7041492704.

The previous prime is 21124478113. The next prime is 21124478147. The reversal of 21124478136 is 63187442112.

It is a junction number, because it is equal to n+sod(n) for n = 21124478094 and 21124478103.

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, 440093271 + ... + 440093318.

Almost surely, 2^21124478136 is an apocalyptic number.

It is an amenable number.

21124478136 is an abundant number, since it is smaller than the sum of its proper divisors (31686717264).

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

21124478136 is a wasteful number, since it uses less digits than its factorization.

21124478136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 880186598 (or 880186594 counting only the distinct ones).

The product of its digits is 64512, while the sum is 39.

The spelling of 21124478136 in words is "twenty-one billion, one hundred twenty-four million, four hundred seventy-eight thousand, one hundred thirty-six".