21995885100 has 288 divisors, whose sum is σ = 74515230720. Its totient is φ = 4905538560.

The previous prime is 21995885077. The next prime is 21995885117. The reversal of 21995885100 is 158859912.

It is a super-2 number, since 2×21995885100² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21995885100.

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, 25487269 + ... + 25488131.

It is an arithmetic number, because the mean of its divisors is an integer number (258733440).

Almost surely, 2^21995885100 is an apocalyptic number.

21995885100 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 21995885100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37257615360).

21995885100 is an abundant number, since it is smaller than the sum of its proper divisors (52519345620).

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

21995885100 is a wasteful number, since it uses less digits than its factorization.

21995885100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1169 (or 1162 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 48.

The spelling of 21995885100 in words is "twenty-one billion, nine hundred ninety-five million, eight hundred eighty-five thousand, one hundred".