21551352600 has 48 divisors (see below), whose sum is σ = 66809194920. Its totient is φ = 5747027200.

The previous prime is 21551352587. The next prime is 21551352607. The reversal of 21551352600 is 625315512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551352607) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17958861 + ... + 17960060.

Almost surely, 2^21551352600 is an apocalyptic number.

21551352600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21551352600 is an abundant number, since it is smaller than the sum of its proper divisors (45257842320).

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

21551352600 is a wasteful number, since it uses less digits than its factorization.

21551352600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35918940 (or 35918931 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

The spelling of 21551352600 in words is "twenty-one billion, five hundred fifty-one million, three hundred fifty-two thousand, six hundred".