312405021 has 12 divisors (see below), whose sum is σ = 470871648. Its totient is φ = 199214664.

The previous prime is 312405017. The next prime is 312405043. The reversal of 312405021 is 120504213.

It is not a de Polignac number, because 312405021 - 2² = 312405017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 312404985 and 312405003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312405061) 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, 754395 + ... + 754808.

It is an arithmetic number, because the mean of its divisors is an integer number (39239304).

Almost surely, 2^312405021 is an apocalyptic number.

It is an amenable number.

312405021 is a deficient number, since it is larger than the sum of its proper divisors (158466627).

312405021 is a wasteful number, since it uses less digits than its factorization.

312405021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1509232 (or 1509229 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 312405021 is about 17674.9829137117. The cubic root of 312405021 is about 678.5356471369.

Adding to 312405021 its reverse (120504213), we get a palindrome (432909234).

The spelling of 312405021 in words is "three hundred twelve million, four hundred five thousand, twenty-one".