21255427600 has 120 divisors (see below), whose sum is σ = 55858424832. Its totient is φ = 7708454400.

The previous prime is 21255427597. The next prime is 21255427601. The reversal of 21255427600 is 672455212.

It is not an unprimeable number, because it can be changed into a prime (21255427601) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1678894 + ... + 1691506.

Almost surely, 2^21255427600 is an apocalyptic number.

21255427600 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 21255427600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27929212416).

21255427600 is an abundant number, since it is smaller than the sum of its proper divisors (34602997232).

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

21255427600 is a wasteful number, since it uses less digits than its factorization.

21255427600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13025 (or 13014 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 34.

The spelling of 21255427600 in words is "twenty-one billion, two hundred fifty-five million, four hundred twenty-seven thousand, six hundred".