12251751921 has 12 divisors (see below), whose sum is σ = 17702579700. Its totient is φ = 8165247840.

The previous prime is 12251751917. The next prime is 12251751959. The reversal of 12251751921 is 12915715221.

12251751921 is a `hidden beast` number, since 1 + 2 + 2 + 517 + 51 + 92 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 515063025 + 11736688896 = 22695^2 + 108336^2 .

It is not a de Polignac number, because 12251751921 - 2² = 12251751917 is a prime.

It is a super-5 number, since 5×12251751921⁵ (a number of 52 digits) contains 55555 as substring.

It is not an unprimeable number, because it can be changed into a prime (12251751971) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 185346 + ... + 242603.

It is an arithmetic number, because the mean of its divisors is an integer number (1475214975).

Almost surely, 2^12251751921 is an apocalyptic number.

It is an amenable number.

12251751921 is a deficient number, since it is larger than the sum of its proper divisors (5450827779).

12251751921 is a wasteful number, since it uses less digits than its factorization.

12251751921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431136 (or 431133 counting only the distinct ones).

The product of its digits is 12600, while the sum is 36.

The spelling of 12251751921 in words is "twelve billion, two hundred fifty-one million, seven hundred fifty-one thousand, nine hundred twenty-one".