31135397 has 4 divisors (see below), whose sum is σ = 31859520. Its totient is φ = 30411276.

The previous prime is 31135393. The next prime is 31135409. The reversal of 31135397 is 79353113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31135397 - 2² = 31135393 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31135393) 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, 361997 + ... + 362082.

It is an arithmetic number, because the mean of its divisors is an integer number (7964880).

Almost surely, 2^31135397 is an apocalyptic number.

It is an amenable number.

31135397 is a deficient number, since it is larger than the sum of its proper divisors (724123).

31135397 is an equidigital number, since it uses as much as digits as its factorization.

31135397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724122.

The product of its digits is 8505, while the sum is 32.

The square root of 31135397 is about 5579.9101247242. The cubic root of 31135397 is about 314.5947488726.

It can be divided in two parts, 3113 and 5397, that multiplied together give a palindrome (16800861).

The spelling of 31135397 in words is "thirty-one million, one hundred thirty-five thousand, three hundred ninety-seven".