31004213021 has 4 divisors (see below), whose sum is σ = 31029037500. Its totient is φ = 30979388544.

The previous prime is 31004212991. The next prime is 31004213027. The reversal of 31004213021 is 12031240013.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14788992100 + 16215220921 = 121610^2 + 127339^2 .

It is a cyclic number.

It is not a de Polignac number, because 31004213021 - 2¹⁸ = 31003950877 is a prime.

It is a super-2 number, since 2×31004213021² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31004213027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12410366 + ... + 12412863.

It is an arithmetic number, because the mean of its divisors is an integer number (7757259375).

Almost surely, 2^31004213021 is an apocalyptic number.

It is an amenable number.

31004213021 is a deficient number, since it is larger than the sum of its proper divisors (24824479).

31004213021 is a wasteful number, since it uses less digits than its factorization.

31004213021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24824478.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 31004213021 its reverse (12031240013), we get a palindrome (43035453034).

The spelling of 31004213021 in words is "thirty-one billion, four million, two hundred thirteen thousand, twenty-one".