31102013021 has 4 divisors (see below), whose sum is σ = 31387352700. Its totient is φ = 30816673344.

The previous prime is 31102012999. The next prime is 31102013053. The reversal of 31102013021 is 12031020113.

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 11403890521 + 19698122500 = 106789^2 + 140350^2 .

It is a cyclic number.

It is not a de Polignac number, because 31102013021 - 2⁶ = 31102012957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31102012987 and 31102013005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31102013221) 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, 142669676 + ... + 142669893.

It is an arithmetic number, because the mean of its divisors is an integer number (7846838175).

Almost surely, 2^31102013021 is an apocalyptic number.

It is an amenable number.

31102013021 is a deficient number, since it is larger than the sum of its proper divisors (285339679).

31102013021 is a wasteful number, since it uses less digits than its factorization.

31102013021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285339678.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 31102013021 its reverse (12031020113), we get a palindrome (43133033134).

The spelling of 31102013021 in words is "thirty-one billion, one hundred two million, thirteen thousand, twenty-one".