31171397 has 4 divisors (see below), whose sum is σ = 31547040. Its totient is φ = 30795756.

The previous prime is 31171373. The next prime is 31171403. The reversal of 31171397 is 79317113.

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 31171397 - 2⁶ = 31171333 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 (31171297) 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, 187697 + ... + 187862.

It is an arithmetic number, because the mean of its divisors is an integer number (7886760).

Almost surely, 2^31171397 is an apocalyptic number.

It is an amenable number.

31171397 is a deficient number, since it is larger than the sum of its proper divisors (375643).

31171397 is an equidigital number, since it uses as much as digits as its factorization.

31171397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375642.

The product of its digits is 3969, while the sum is 32.

The square root of 31171397 is about 5583.1350512056. The cubic root of 31171397 is about 314.7159512112.

The spelling of 31171397 in words is "thirty-one million, one hundred seventy-one thousand, three hundred ninety-seven".