21253813375 has 16 divisors (see below), whose sum is σ = 26974340640. Its totient is φ = 16714857600.

The previous prime is 21253813363. The next prime is 21253813379. The reversal of 21253813375 is 57331835212.

It is not a de Polignac number, because 21253813375 - 2⁷ = 21253813247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253813379) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1433562 + ... + 1448311.

It is an arithmetic number, because the mean of its divisors is an integer number (1685896290).

Almost surely, 2^21253813375 is an apocalyptic number.

21253813375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21253813375 is a deficient number, since it is larger than the sum of its proper divisors (5720527265).

21253813375 is an equidigital number, since it uses as much as digits as its factorization.

21253813375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2881947 (or 2881937 counting only the distinct ones).

The product of its digits is 151200, while the sum is 40.

The spelling of 21253813375 in words is "twenty-one billion, two hundred fifty-three million, eight hundred thirteen thousand, three hundred seventy-five".