21136898225 has 24 divisors (see below), whose sum is σ = 27523625280. Its totient is φ = 16071232320.

The previous prime is 21136898191. The next prime is 21136898227. The reversal of 21136898225 is 52289863112.

It is a happy number.

It is not a de Polignac number, because 21136898225 - 2²⁶ = 21069789361 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21136898225.

It is not an unprimeable number, because it can be changed into a prime (21136898227) 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, 26795 + ... + 207344.

It is an arithmetic number, because the mean of its divisors is an integer number (1146817720).

Almost surely, 2^21136898225 is an apocalyptic number.

21136898225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21136898225 is a deficient number, since it is larger than the sum of its proper divisors (6386727055).

21136898225 is a wasteful number, since it uses less digits than its factorization.

21136898225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234329 (or 234324 counting only the distinct ones).

The product of its digits is 414720, while the sum is 47.

The spelling of 21136898225 in words is "twenty-one billion, one hundred thirty-six million, eight hundred ninety-eight thousand, two hundred twenty-five".