21965022720 has 960 divisors, whose sum is σ = 87510398976. Its totient is φ = 5255331840.

The previous prime is 21965022691. The next prime is 21965022749. The reversal of 21965022720 is 2722056912.

It is a happy number.

21965022720 is a `hidden beast` number, since 21 + 96 + 502 + 27 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (21965022691) and next prime (21965022749).

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 327836127 + ... + 327836193.

Almost surely, 2^21965022720 is an apocalyptic number.

21965022720 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 21965022720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43755199488).

21965022720 is an abundant number, since it is smaller than the sum of its proper divisors (65545376256).

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

21965022720 is an equidigital number, since it uses as much as digits as its factorization.

21965022720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 21965022720 in words is "twenty-one billion, nine hundred sixty-five million, twenty-two thousand, seven hundred twenty".