31121043021 has 48 divisors (see below), whose sum is σ = 48331315200. Its totient is φ = 19790008128.

The previous prime is 31121043001. The next prime is 31121043043. The reversal of 31121043021 is 12034012113.

31121043021 is a `hidden beast` number, since 3 + 1 + 1 + 210 + 430 + 21 = 666.

It is not a de Polignac number, because 31121043021 - 2⁷ = 31121042893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31121042985 and 31121043003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31121043001) 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 47 ways as a sum of consecutive naturals, for example, 5467545 + ... + 5473233.

It is an arithmetic number, because the mean of its divisors is an integer number (1006902400).

Almost surely, 2^31121043021 is an apocalyptic number.

It is an amenable number.

31121043021 is a deficient number, since it is larger than the sum of its proper divisors (17210272179).

31121043021 is a wasteful number, since it uses less digits than its factorization.

31121043021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6127 (or 6098 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 31121043021 its reverse (12034012113), we get a palindrome (43155055134).

The spelling of 31121043021 in words is "thirty-one billion, one hundred twenty-one million, forty-three thousand, twenty-one".