21920700864 has 168 divisors, whose sum is σ = 61983152640. Its totient is φ = 6835564544.

The previous prime is 21920700817. The next prime is 21920700869. The reversal of 21920700864 is 46800702912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21920700869) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9931249 + ... + 9933455.

Almost surely, 2^21920700864 is an apocalyptic number.

21920700864 is a gapful number since it is divisible by the number (24) 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 21920700864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30991576320).

21920700864 is an abundant number, since it is smaller than the sum of its proper divisors (40062451776).

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

21920700864 is a wasteful number, since it uses less digits than its factorization.

21920700864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2435 (or 2408 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 39.

The spelling of 21920700864 in words is "twenty-one billion, nine hundred twenty million, seven hundred thousand, eight hundred sixty-four".