21197072250 has 96 divisors (see below), whose sum is σ = 59439901248. Its totient is φ = 5652536400.

The previous prime is 21197072231. The next prime is 21197072257. The reversal of 21197072250 is 5227079112.

It is not an unprimeable number, because it can be changed into a prime (21197072257) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 113712 + ... + 235211.

It is an arithmetic number, because the mean of its divisors is an integer number (619165638).

Almost surely, 2^21197072250 is an apocalyptic number.

21197072250 is an abundant number, since it is smaller than the sum of its proper divisors (38242828998).

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

21197072250 is an equidigital number, since it uses as much as digits as its factorization.

21197072250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348955 (or 348933 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 36.

The spelling of 21197072250 in words is "twenty-one billion, one hundred ninety-seven million, seventy-two thousand, two hundred fifty".