312121312021 has 16 divisors (see below), whose sum is σ = 326487490560. Its totient is φ = 297822001840.

The previous prime is 312121311991. The next prime is 312121312031. The reversal of 312121312021 is 120213121213.

It is a cyclic number.

It is not a de Polignac number, because 312121312021 - 2¹³ = 312121303829 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 312121312021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312121312031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33302466 + ... + 33311836.

It is an arithmetic number, because the mean of its divisors is an integer number (20405468160).

Almost surely, 2^312121312021 is an apocalyptic number.

It is an amenable number.

312121312021 is a deficient number, since it is larger than the sum of its proper divisors (14366178539).

312121312021 is a wasteful number, since it uses less digits than its factorization.

312121312021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12776.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 312121312021 its reverse (120213121213), we get a palindrome (432334433234).

The spelling of 312121312021 in words is "three hundred twelve billion, one hundred twenty-one million, three hundred twelve thousand, twenty-one".