21463744538 has 16 divisors (see below), whose sum is σ = 33311402280. Its totient is φ = 10360068096.

The previous prime is 21463744517. The next prime is 21463744543. The reversal of 21463744538 is 83544736412.

It can be written as a sum of positive squares in 4 ways, for example, as 5211829249 + 16251915289 = 72193^2 + 127483^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21463744492 and 21463744501.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 359306 + ... + 414762.

Almost surely, 2^21463744538 is an apocalyptic number.

21463744538 is a deficient number, since it is larger than the sum of its proper divisors (11847657742).

21463744538 is a wasteful number, since it uses less digits than its factorization.

21463744538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62161.

The product of its digits is 1935360, while the sum is 47.

The spelling of 21463744538 in words is "twenty-one billion, four hundred sixty-three million, seven hundred forty-four thousand, five hundred thirty-eight".