21975299808 has 384 divisors, whose sum is σ = 73667543040. Its totient is φ = 5617497600.

The previous prime is 21975299807. The next prime is 21975299861. The reversal of 21975299808 is 80899257912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21975299807) 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, 70659973 + ... + 70660283.

It is an arithmetic number, because the mean of its divisors is an integer number (191842560).

Almost surely, 2^21975299808 is an apocalyptic number.

21975299808 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 21975299808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36833771520).

21975299808 is an abundant number, since it is smaller than the sum of its proper divisors (51692243232).

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

21975299808 is a wasteful number, since it uses less digits than its factorization.

21975299808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443 (or 413 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 60.

The spelling of 21975299808 in words is "twenty-one billion, nine hundred seventy-five million, two hundred ninety-nine thousand, eight hundred eight".