31713157 has 4 divisors (see below), whose sum is σ = 36243616. Its totient is φ = 27182700.

The previous prime is 31713137. The next prime is 31713161. The reversal of 31713157 is 75131713.

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, and also an emirpimes, since its reverse is a distinct semiprime: 75131713 = 877 ⋅85669.

It is a cyclic number.

It is not a de Polignac number, because 31713157 - 2¹⁹ = 31188869 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 (31713127) 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, 2265219 + ... + 2265232.

It is an arithmetic number, because the mean of its divisors is an integer number (9060904).

Almost surely, 2^31713157 is an apocalyptic number.

It is an amenable number.

31713157 is a deficient number, since it is larger than the sum of its proper divisors (4530459).

31713157 is an equidigital number, since it uses as much as digits as its factorization.

31713157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4530458.

The product of its digits is 2205, while the sum is 28.

The square root of 31713157 is about 5631.4435982259. The cubic root of 31713157 is about 316.5287474502.

It can be divided in two parts, 3171 and 3157, that added together give a triangular number (6328 = T₁₁₂).

The spelling of 31713157 in words is "thirty-one million, seven hundred thirteen thousand, one hundred fifty-seven".