21501513164 has 12 divisors (see below), whose sum is σ = 39841039224. Its totient is φ = 10118359104.

The previous prime is 21501513161. The next prime is 21501513199. The reversal of 21501513164 is 46131510512.

It is not an unprimeable number, because it can be changed into a prime (21501513161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158099294 + ... + 158099429.

It is an arithmetic number, because the mean of its divisors is an integer number (3320086602).

Almost surely, 2^21501513164 is an apocalyptic number.

It is an amenable number.

21501513164 is a deficient number, since it is larger than the sum of its proper divisors (18339526060).

21501513164 is a wasteful number, since it uses less digits than its factorization.

21501513164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316198744 (or 316198742 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 29.

The spelling of 21501513164 in words is "twenty-one billion, five hundred one million, five hundred thirteen thousand, one hundred sixty-four".