21297885275 has 6 divisors (see below), whose sum is σ = 26409377772. Its totient is φ = 17038308200.

The previous prime is 21297885263. The next prime is 21297885281. The reversal of 21297885275 is 57258879212.

It is not a de Polignac number, because 21297885275 - 2¹² = 21297881179 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21297885275.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 425957681 + ... + 425957730.

It is an arithmetic number, because the mean of its divisors is an integer number (4401562962).

Almost surely, 2^21297885275 is an apocalyptic number.

21297885275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21297885275 is a deficient number, since it is larger than the sum of its proper divisors (5111492497).

21297885275 is an equidigital number, since it uses as much as digits as its factorization.

21297885275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 851915421 (or 851915416 counting only the distinct ones).

The product of its digits is 5644800, while the sum is 56.

The spelling of 21297885275 in words is "twenty-one billion, two hundred ninety-seven million, eight hundred eighty-five thousand, two hundred seventy-five".