31138733 has 4 divisors (see below), whose sum is σ = 31274940. Its totient is φ = 31002528.

The previous prime is 31138699. The next prime is 31138741. The reversal of 31138733 is 33783113.

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 28536964 + 2601769 = 5342^2 + 1613^2 .

It is a cyclic number.

It is not a de Polignac number, because 31138733 - 2⁶ = 31138669 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31138696 and 31138705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31138763) 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, 67760 + ... + 68217.

It is an arithmetic number, because the mean of its divisors is an integer number (7818735).

Almost surely, 2^31138733 is an apocalyptic number.

It is an amenable number.

31138733 is a deficient number, since it is larger than the sum of its proper divisors (136207).

31138733 is a wasteful number, since it uses less digits than its factorization.

31138733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136206.

The product of its digits is 4536, while the sum is 29.

The square root of 31138733 is about 5580.2090462634. The cubic root of 31138733 is about 314.6059842157.

The spelling of 31138733 in words is "thirty-one million, one hundred thirty-eight thousand, seven hundred thirty-three".