21920998680 has 384 divisors, whose sum is σ = 85277836800. Its totient is φ = 4994148096.

The previous prime is 21920998661. The next prime is 21920998739. The reversal of 21920998680 is 8689902912.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 24713197 + ... + 24714083.

It is an arithmetic number, because the mean of its divisors is an integer number (222077700).

Almost surely, 2^21920998680 is an apocalyptic number.

21920998680 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 21920998680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42638918400).

21920998680 is an abundant number, since it is smaller than the sum of its proper divisors (63356838120).

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

21920998680 is a wasteful number, since it uses less digits than its factorization.

21920998680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1388 (or 1371 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 21920998680 in words is "twenty-one billion, nine hundred twenty million, nine hundred ninety-eight thousand, six hundred eighty".