31686427 has 4 divisors (see below), whose sum is σ = 32000256. Its totient is φ = 31372600.

The previous prime is 31686367. The next prime is 31686437. The reversal of 31686427 is 72468613.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31686427 - 2¹⁵ = 31653659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31686437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156763 + ... + 156964.

It is an arithmetic number, because the mean of its divisors is an integer number (8000064).

Almost surely, 2^31686427 is an apocalyptic number.

31686427 is a deficient number, since it is larger than the sum of its proper divisors (313829).

31686427 is a wasteful number, since it uses less digits than its factorization.

31686427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313828.

The product of its digits is 48384, while the sum is 37.

The square root of 31686427 is about 5629.0698165860. The cubic root of 31686427 is about 316.4397918194.

The spelling of 31686427 in words is "thirty-one million, six hundred eighty-six thousand, four hundred twenty-seven".