31204213021 has 4 divisors (see below), whose sum is σ = 31228999200. Its totient is φ = 31179426844.

The previous prime is 31204212983. The next prime is 31204213043. The reversal of 31204213021 is 12031240213.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31204213021 - 2¹⁷ = 31204081949 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 31204213021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31204213721) 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 3 ways as a sum of consecutive naturals, for example, 12391201 + ... + 12393718.

It is an arithmetic number, because the mean of its divisors is an integer number (7807249800).

Almost surely, 2^31204213021 is an apocalyptic number.

It is an amenable number.

31204213021 is a deficient number, since it is larger than the sum of its proper divisors (24786179).

31204213021 is a wasteful number, since it uses less digits than its factorization.

31204213021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24786178.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 31204213021 its reverse (12031240213), we get a palindrome (43235453234).

The spelling of 31204213021 in words is "thirty-one billion, two hundred four million, two hundred thirteen thousand, twenty-one".