21044206164 has 48 divisors (see below), whose sum is σ = 49334648832. Its totient is φ = 6981743712.

The previous prime is 21044206133. The next prime is 21044206171. The reversal of 21044206164 is 46160244012.

It is a happy number.

It is a super-2 number, since 2×21044206164² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2307237 + ... + 2316339.

It is an arithmetic number, because the mean of its divisors is an integer number (1027805184).

Almost surely, 2^21044206164 is an apocalyptic number.

It is an amenable number.

21044206164 is an abundant number, since it is smaller than the sum of its proper divisors (28290442668).

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

21044206164 is a wasteful number, since it uses less digits than its factorization.

21044206164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9996 (or 9994 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The spelling of 21044206164 in words is "twenty-one billion, forty-four million, two hundred six thousand, one hundred sixty-four".