12400251021 has 24 divisors (see below), whose sum is σ = 18052580000. Its totient is φ = 8201790432.

The previous prime is 12400251013. The next prime is 12400251023. The reversal of 12400251021 is 12015200421.

12400251021 is a `hidden beast` number, since 12 + 400 + 251 + 0 + 2 + 1 = 666.

It is not a de Polignac number, because 12400251021 - 2³ = 12400251013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12400250985 and 12400251003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12400251023) 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, 2723655 + ... + 2728203.

Almost surely, 2^12400251021 is an apocalyptic number.

It is an amenable number.

12400251021 is a deficient number, since it is larger than the sum of its proper divisors (5652328979).

12400251021 is a wasteful number, since it uses less digits than its factorization.

12400251021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6873 (or 6870 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

Adding to 12400251021 its reverse (12015200421), we get a palindrome (24415451442).

The spelling of 12400251021 in words is "twelve billion, four hundred million, two hundred fifty-one thousand, twenty-one".