21225817900 has 36 divisors (see below), whose sum is σ = 52640030128. Its totient is φ = 7277423040.

The previous prime is 21225817859. The next prime is 21225817903. The reversal of 21225817900 is 971852212.

It is a self number, because there is not a number n which added to its sum of digits gives 21225817900.

It is not an unprimeable number, because it can be changed into a prime (21225817903) 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, 15160599 + ... + 15161998.

Almost surely, 2^21225817900 is an apocalyptic number.

21225817900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21225817900 is an abundant number, since it is smaller than the sum of its proper divisors (31414212228).

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

21225817900 is a wasteful number, since it uses less digits than its factorization.

21225817900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30322618 (or 30322611 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 37.

The spelling of 21225817900 in words is "twenty-one billion, two hundred twenty-five million, eight hundred seventeen thousand, nine hundred".