21479765796 has 18 divisors (see below), whose sum is σ = 54296074742. Its totient is φ = 7159921920.

The previous prime is 21479765789. The next prime is 21479765809. The reversal of 21479765796 is 69756797412.

21479765796 is a `hidden beast` number, since 2 + 1 + 479 + 76 + 5 + 7 + 96 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21468110400 + 11655396 = 146520^2 + 3414^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×21479765796² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 298330045 + ... + 298330116.

Almost surely, 2^21479765796 is an apocalyptic number.

It is an amenable number.

21479765796 is an abundant number, since it is smaller than the sum of its proper divisors (32816308946).

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

21479765796 is a wasteful number, since it uses less digits than its factorization.

21479765796 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596660171 (or 596660166 counting only the distinct ones).

The product of its digits is 40007520, while the sum is 63.

The spelling of 21479765796 in words is "twenty-one billion, four hundred seventy-nine million, seven hundred sixty-five thousand, seven hundred ninety-six".