312031021 has 4 divisors (see below), whose sum is σ = 312100992. Its totient is φ = 311961052.

The previous prime is 312030997. The next prime is 312031121. The reversal of 312031021 is 120130213.

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 not a de Polignac number, because 312031021 - 2¹³ = 312022829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 312030992 and 312031010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312031121) 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, 27805 + ... + 37378.

It is an arithmetic number, because the mean of its divisors is an integer number (78025248).

Almost surely, 2^312031021 is an apocalyptic number.

It is an amenable number.

312031021 is a deficient number, since it is larger than the sum of its proper divisors (69971).

312031021 is an equidigital number, since it uses as much as digits as its factorization.

312031021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69970.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 312031021 is about 17664.3998199769. The cubic root of 312031021 is about 678.2647662276.

Adding to 312031021 its reverse (120130213), we get a palindrome (432161234).

The spelling of 312031021 in words is "three hundred twelve million, thirty-one thousand, twenty-one".