31312122120021 has 8 divisors (see below), whose sum is σ = 41749549975584. Its totient is φ = 20874721172240.

The previous prime is 31312122120001. The next prime is 31312122120031. The reversal of 31312122120021 is 12002122121313.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31312122120021 - 2¹⁴ = 31312122103637 is a prime.

It is a super-3 number, since 3×31312122120021³ (a number of 41 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31312122120021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31312122120001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3833946 + ... + 8793371.

It is an arithmetic number, because the mean of its divisors is an integer number (5218693746948).

Almost surely, 2^{31312122120021} is an apocalyptic number.

It is an amenable number.

31312122120021 is a deficient number, since it is larger than the sum of its proper divisors (10437427855563).

31312122120021 is a wasteful number, since it uses less digits than its factorization.

31312122120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13453891.

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 31312122120021 its reverse (12002122121313), we get a palindrome (43314244241334).

The spelling of 31312122120021 in words is "thirty-one trillion, three hundred twelve billion, one hundred twenty-two million, one hundred twenty thousand, twenty-one".