124312400021 has 4 divisors (see below), whose sum is σ = 127203386112. Its totient is φ = 121421413932.

The previous prime is 124312399979. The next prime is 124312400027. The reversal of 124312400021 is 120004213421.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-124312400021 is a prime.

It is a super-2 number, since 2×124312400021² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 124312399966 and 124312400002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (124312400027) 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, 1445492981 + ... + 1445493066.

It is an arithmetic number, because the mean of its divisors is an integer number (31800846528).

Almost surely, 2^124312400021 is an apocalyptic number.

It is an amenable number.

124312400021 is a deficient number, since it is larger than the sum of its proper divisors (2890986091).

124312400021 is an equidigital number, since it uses as much as digits as its factorization.

124312400021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2890986090.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 124312400021 its reverse (120004213421), we get a palindrome (244316613442).

The spelling of 124312400021 in words is "one hundred twenty-four billion, three hundred twelve million, four hundred thousand, twenty-one".