21513275768 has 32 divisors (see below), whose sum is σ = 44306524800. Its totient is φ = 9747432288.

The previous prime is 21513275761. The next prime is 21513275843. The reversal of 21513275768 is 86757231512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513275761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3073346 + ... + 3080337.

It is an arithmetic number, because the mean of its divisors is an integer number (1384578900).

Almost surely, 2^21513275768 is an apocalyptic number.

It is an amenable number.

21513275768 is an abundant number, since it is smaller than the sum of its proper divisors (22793249032).

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

21513275768 is a wasteful number, since it uses less digits than its factorization.

21513275768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6153731 (or 6153727 counting only the distinct ones).

The product of its digits is 705600, while the sum is 47.

The spelling of 21513275768 in words is "twenty-one billion, five hundred thirteen million, two hundred seventy-five thousand, seven hundred sixty-eight".