31317205247 has 4 divisors (see below), whose sum is σ = 31319317920. Its totient is φ = 31315092576.

The previous prime is 31317205189. The next prime is 31317205273. The reversal of 31317205247 is 74250271313.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74250271313 = 147977 ⋅501769.

It is a cyclic number.

It is not a de Polignac number, because 31317205247 - 2¹⁸ = 31316943103 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 (31317405247) 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, 1033943 + ... + 1063800.

It is an arithmetic number, because the mean of its divisors is an integer number (7829829480).

Almost surely, 2^31317205247 is an apocalyptic number.

31317205247 is a deficient number, since it is larger than the sum of its proper divisors (2112673).

31317205247 is a wasteful number, since it uses less digits than its factorization.

31317205247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2112672.

The product of its (nonzero) digits is 35280, while the sum is 35.

The spelling of 31317205247 in words is "thirty-one billion, three hundred seventeen million, two hundred five thousand, two hundred forty-seven".