31212021021 has 16 divisors (see below), whose sum is σ = 42536771136. Its totient is φ = 20350152576.

The previous prime is 31212021013. The next prime is 31212021079. The reversal of 31212021021 is 12012021213.

It is not a de Polignac number, because 31212021021 - 2³ = 31212021013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31212021521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 263815 + ... + 363348.

It is an arithmetic number, because the mean of its divisors is an integer number (2658548196).

Almost surely, 2^31212021021 is an apocalyptic number.

It is an amenable number.

31212021021 is a deficient number, since it is larger than the sum of its proper divisors (11324750115).

31212021021 is a wasteful number, since it uses less digits than its factorization.

31212021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 627532.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 31212021021 its reverse (12012021213), we get a palindrome (43224042234).

The spelling of 31212021021 in words is "thirty-one billion, two hundred twelve million, twenty-one thousand, twenty-one".