21015764934 has 12 divisors (see below), whose sum is σ = 42032240076. Its totient is φ = 7005136612.

The previous prime is 21015764933. The next prime is 21015764963. The reversal of 21015764934 is 43946751012.

21015764934 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×21015764934² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21015764933) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 325507 + ... + 384689.

It is an arithmetic number, because the mean of its divisors is an integer number (3502686673).

Almost surely, 2^21015764934 is an apocalyptic number.

21015764934 is an abundant number, since it is smaller than the sum of its proper divisors (21016475142).

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

21015764934 is an frugal number, since it uses more digits than its factorization.

21015764934 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118371 (or 59188 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 42.

The spelling of 21015764934 in words is "twenty-one billion, fifteen million, seven hundred sixty-four thousand, nine hundred thirty-four".