21919779161280 has 2688 divisors, whose sum is σ = 105589235404800. Its totient is φ = 4165142446080.

The previous prime is 21919779161261. The next prime is 21919779161309. The reversal of 21919779161280 is 8216197791912.

21919779161280 is a `hidden beast` number, since 2 + 1 + 9 + 1 + 9 + 7 + 7 + 9 + 1 + 612 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 10750258501 + ... + 10750260539.

It is an arithmetic number, because the mean of its divisors is an integer number (39281709600).

Almost surely, 2^{21919779161280} is an apocalyptic number.

21919779161280 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 21919779161280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52794617702400).

21919779161280 is an abundant number, since it is smaller than the sum of its proper divisors (83669456243520).

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

21919779161280 is a wasteful number, since it uses less digits than its factorization.

21919779161280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2220 (or 2193 counting only the distinct ones).

The product of its (nonzero) digits is 6858432, while the sum is 63.

The spelling of 21919779161280 in words is "twenty-one trillion, nine hundred nineteen billion, seven hundred seventy-nine million, one hundred sixty-one thousand, two hundred eighty".