21979141699680 has 576 divisors, whose sum is σ = 85907271340800. Its totient is φ = 5067751772160.

The previous prime is 21979141699597. The next prime is 21979141699699. The reversal of 21979141699680 is 8699614197912.

21979141699680 is a `hidden beast` number, since 219 + 7 + 91 + 4 + 169 + 96 + 80 = 666.

It is a super-2 number, since 2×21979141699680² (a number of 27 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 21979141699599 and 21979141699608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 30420051 + ... + 31134189.

It is an arithmetic number, because the mean of its divisors is an integer number (149144568300).

Almost surely, 2^{21979141699680} is an apocalyptic number.

21979141699680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21979141699680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42953635670400).

21979141699680 is an abundant number, since it is smaller than the sum of its proper divisors (63928129641120).

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

21979141699680 is a wasteful number, since it uses less digits than its factorization.

21979141699680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 714267 (or 714256 counting only the distinct ones).

The product of its (nonzero) digits is 105815808, while the sum is 72.

The spelling of 21979141699680 in words is "twenty-one trillion, nine hundred seventy-nine billion, one hundred forty-one million, six hundred ninety-nine thousand, six hundred eighty".