21247148538 has 48 divisors (see below), whose sum is σ = 57394898496. Its totient is φ = 5518739520.

The previous prime is 21247148521. The next prime is 21247148551. The reversal of 21247148538 is 83584174212.

21247148538 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 71 + 48 + 538 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21247148493 and 21247148502.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7663531 + ... + 7666302.

It is an arithmetic number, because the mean of its divisors is an integer number (1195727052).

Almost surely, 2^21247148538 is an apocalyptic number.

21247148538 is an abundant number, since it is smaller than the sum of its proper divisors (36147749958).

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

21247148538 is a wasteful number, since it uses less digits than its factorization.

21247148538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15329859 (or 15329856 counting only the distinct ones).

The product of its digits is 430080, while the sum is 45.

The spelling of 21247148538 in words is "twenty-one billion, two hundred forty-seven million, one hundred forty-eight thousand, five hundred thirty-eight".