21608671100 has 72 divisors (see below), whose sum is σ = 49717317888. Its totient is φ = 8123852800.

The previous prime is 21608671067. The next prime is 21608671127. The reversal of 21608671100 is 117680612.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1285349 + ... + 1302051.

It is an arithmetic number, because the mean of its divisors is an integer number (690518304).

Almost surely, 2^21608671100 is an apocalyptic number.

21608671100 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 21608671100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24858658944).

21608671100 is an abundant number, since it is smaller than the sum of its proper divisors (28108646788).

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

21608671100 is a wasteful number, since it uses less digits than its factorization.

21608671100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17495 (or 17488 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 32.

The spelling of 21608671100 in words is "twenty-one billion, six hundred eight million, six hundred seventy-one thousand, one hundred".