31031212021 has 16 divisors (see below), whose sum is σ = 32944713984. Its totient is φ = 29127631104.

The previous prime is 31031211979. The next prime is 31031212027. The reversal of 31031212021 is 12021213013.

It is a cyclic number.

It is not a de Polignac number, because 31031212021 - 2³³ = 22441277429 is a prime.

It is a super-2 number, since 2×31031212021² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31031211986 and 31031212004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31031212027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15114031 + ... + 15116083.

It is an arithmetic number, because the mean of its divisors is an integer number (2059044624).

Almost surely, 2^31031212021 is an apocalyptic number.

It is an amenable number.

31031212021 is a deficient number, since it is larger than the sum of its proper divisors (1913501963).

31031212021 is a wasteful number, since it uses less digits than its factorization.

31031212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4020.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 31031212021 its reverse (12021213013), we get a palindrome (43052425034).

The spelling of 31031212021 in words is "thirty-one billion, thirty-one million, two hundred twelve thousand, twenty-one".