31122320021 has 16 divisors (see below), whose sum is σ = 35061692400. Its totient is φ = 27425975808.

The previous prime is 31122319973. The next prime is 31122320039. The reversal of 31122320021 is 12002322113.

It can be written as a sum of positive squares in 8 ways, for example, as 1524902500 + 29597417521 = 39050^2 + 172039^2 .

It is a cyclic number.

It is not a de Polignac number, because 31122320021 - 2⁶ = 31122319957 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31122325021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 430226 + ... + 497331.

It is an arithmetic number, because the mean of its divisors is an integer number (2191355775).

Almost surely, 2^31122320021 is an apocalyptic number.

It is an amenable number.

31122320021 is a deficient number, since it is larger than the sum of its proper divisors (3939372379).

31122320021 is a wasteful number, since it uses less digits than its factorization.

31122320021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 927688.

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

Adding to 31122320021 its reverse (12002322113), we get a palindrome (43124642134).

The spelling of 31122320021 in words is "thirty-one billion, one hundred twenty-two million, three hundred twenty thousand, twenty-one".