21979813360 has 20 divisors (see below), whose sum is σ = 51103066248. Its totient is φ = 8791925312.

The previous prime is 21979813319. The next prime is 21979813367. The reversal of 21979813360 is 6331897912.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×21979813360² (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 (21979813367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137373754 + ... + 137373913.

Almost surely, 2^21979813360 is an apocalyptic number.

21979813360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21979813360 is an abundant number, since it is smaller than the sum of its proper divisors (29123252888).

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

21979813360 is a wasteful number, since it uses less digits than its factorization.

21979813360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274747680 (or 274747674 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 49.

The spelling of 21979813360 in words is "twenty-one billion, nine hundred seventy-nine million, eight hundred thirteen thousand, three hundred sixty".