21112501253 has 4 divisors (see below), whose sum is σ = 21427613280. Its totient is φ = 20797389228.

The previous prime is 21112501247. The next prime is 21112501259. The reversal of 21112501253 is 35210521112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (21112501247) and next prime (21112501259).

It is a cyclic number.

It is not a de Polignac number, because 21112501253 - 2²² = 21108306949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112501259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157555913 + ... + 157556046.

It is an arithmetic number, because the mean of its divisors is an integer number (5356903320).

Almost surely, 2^21112501253 is an apocalyptic number.

It is an amenable number.

21112501253 is a deficient number, since it is larger than the sum of its proper divisors (315112027).

21112501253 is an equidigital number, since it uses as much as digits as its factorization.

21112501253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315112026.

The product of its (nonzero) digits is 600, while the sum is 23.

The spelling of 21112501253 in words is "twenty-one billion, one hundred twelve million, five hundred one thousand, two hundred fifty-three".