21158464844 has 96 divisors (see below), whose sum is σ = 43421736960. Its totient is φ = 8926444800.

The previous prime is 21158464793. The next prime is 21158464871. The reversal of 21158464844 is 44846485112.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6208589 + ... + 6211995.

It is an arithmetic number, because the mean of its divisors is an integer number (452309760).

Almost surely, 2^21158464844 is an apocalyptic number.

It is an amenable number.

21158464844 is an abundant number, since it is smaller than the sum of its proper divisors (22263272116).

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

21158464844 is a wasteful number, since it uses less digits than its factorization.

21158464844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3639 (or 3637 counting only the distinct ones).

The product of its digits is 983040, while the sum is 47.

The spelling of 21158464844 in words is "twenty-one billion, one hundred fifty-eight million, four hundred sixty-four thousand, eight hundred forty-four".