31133220031 has 4 divisors (see below), whose sum is σ = 31155038712. Its totient is φ = 31111401352.

The previous prime is 31133219963. The next prime is 31133220043. The reversal of 31133220031 is 13002233113.

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

It is a cyclic number.

It is not a de Polignac number, because 31133220031 - 2¹³ = 31133211839 is a prime.

It is a super-2 number, since 2×31133220031² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31133219990 and 31133220008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31133220731) 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, 10907200 + ... + 10910053.

It is an arithmetic number, because the mean of its divisors is an integer number (7788759678).

Almost surely, 2^31133220031 is an apocalyptic number.

31133220031 is a deficient number, since it is larger than the sum of its proper divisors (21818681).

31133220031 is a wasteful number, since it uses less digits than its factorization.

31133220031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21818680.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 31133220031 its reverse (13002233113), we get a palindrome (44135453144).

The spelling of 31133220031 in words is "thirty-one billion, one hundred thirty-three million, two hundred twenty thousand, thirty-one".