31391688194 has 8 divisors (see below), whose sum is σ = 47553745788. Its totient is φ = 15540439600.

The previous prime is 31391688191. The next prime is 31391688199. The reversal of 31391688194 is 49188619313.

It can be written as a sum of positive squares in 2 ways, for example, as 20302545169 + 11089143025 = 142487^2 + 105305^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (31391688191) 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, 77701997 + ... + 77702400.

Almost surely, 2^31391688194 is an apocalyptic number.

31391688194 is a deficient number, since it is larger than the sum of its proper divisors (16162057594).

31391688194 is a wasteful number, since it uses less digits than its factorization.

31391688194 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155404500.

The product of its digits is 1119744, while the sum is 53.

The spelling of 31391688194 in words is "thirty-one billion, three hundred ninety-one million, six hundred eighty-eight thousand, one hundred ninety-four".