21999564048 has 320 divisors, whose sum is σ = 74852352000. Its totient is φ = 5394055680.

The previous prime is 21999564047. The next prime is 21999564049. The reversal of 21999564048 is 84046599912.

It is an interprime number because it is at equal distance from previous prime (21999564047) and next prime (21999564049).

It is a hoax number, since the sum of its digits (57) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (21999564047) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 36726853 + ... + 36727451.

It is an arithmetic number, because the mean of its divisors is an integer number (233913600).

Almost surely, 2^21999564048 is an apocalyptic number.

21999564048 is a gapful number since it is divisible by the number (28) 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 21999564048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37426176000).

21999564048 is an abundant number, since it is smaller than the sum of its proper divisors (52852787952).

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

21999564048 is a wasteful number, since it uses less digits than its factorization.

21999564048 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1170 (or 1164 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 57.

The spelling of 21999564048 in words is "twenty-one billion, nine hundred ninety-nine million, five hundred sixty-four thousand, forty-eight".