21029731844 has 12 divisors (see below), whose sum is σ = 40147669968. Its totient is φ = 9558969000.

The previous prime is 21029731837. The next prime is 21029731861. The reversal of 21029731844 is 44813792012.

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, 238974182 + ... + 238974269.

It is an arithmetic number, because the mean of its divisors is an integer number (3345639164).

Almost surely, 2^21029731844 is an apocalyptic number.

It is an amenable number.

21029731844 is a deficient number, since it is larger than the sum of its proper divisors (19117938124).

21029731844 is a wasteful number, since it uses less digits than its factorization.

21029731844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477948466 (or 477948464 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 41.

The spelling of 21029731844 in words is "twenty-one billion, twenty-nine million, seven hundred thirty-one thousand, eight hundred forty-four".