312100021 has 4 divisors (see below), whose sum is σ = 312268000. Its totient is φ = 311932044.

The previous prime is 312100013. The next prime is 312100031. The reversal of 312100021 is 120001213.

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 312100021 - 2³ = 312100013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 312099980 and 312100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312100031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81171 + ... + 84928.

It is an arithmetic number, because the mean of its divisors is an integer number (78067000).

Almost surely, 2^312100021 is an apocalyptic number.

It is an amenable number.

312100021 is a deficient number, since it is larger than the sum of its proper divisors (167979).

312100021 is a wasteful number, since it uses less digits than its factorization.

312100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167978.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 312100021 is about 17666.3527928093. The cubic root of 312100021 is about 678.3147578593.

Adding to 312100021 its reverse (120001213), we get a palindrome (432101234).

The spelling of 312100021 in words is "three hundred twelve million, one hundred thousand, twenty-one".