21252744825 has 48 divisors (see below), whose sum is σ = 37873992576. Its totient is φ = 10453708800.

The previous prime is 21252744811. The next prime is 21252744839. The reversal of 21252744825 is 52844725212.

It is an interprime number because it is at equal distance from previous prime (21252744811) and next prime (21252744839).

It is not a de Polignac number, because 21252744825 - 2⁶ = 21252744761 is a prime.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1177620 + ... + 1195530.

It is an arithmetic number, because the mean of its divisors is an integer number (789041512).

Almost surely, 2^21252744825 is an apocalyptic number.

21252744825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21252744825 is a deficient number, since it is larger than the sum of its proper divisors (16621247751).

21252744825 is a wasteful number, since it uses less digits than its factorization.

21252744825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19154 (or 19149 counting only the distinct ones).

The product of its digits is 358400, while the sum is 42.

The spelling of 21252744825 in words is "twenty-one billion, two hundred fifty-two million, seven hundred forty-four thousand, eight hundred twenty-five".