31690 has 8 divisors (see below), whose sum is σ = 57060. Its totient is φ = 12672.

The previous prime is 31687. The next prime is 31699. The reversal of 31690 is 9613.

31690 = T₄₆ + T₄₇ + ... + T₆₅.

It can be written as a sum of positive squares in 2 ways, for example, as 31329 + 361 = 177^2 + 19^2 .

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

It is a super-2 number, since 2×31690² = 2008512200, which contains 22 as substring.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (31699) 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, 1575 + ... + 1594.

2³¹⁶⁹⁰ is an apocalyptic number.

31690 is a deficient number, since it is larger than the sum of its proper divisors (25370).

31690 is a wasteful number, since it uses less digits than its factorization.

31690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3176.

The product of its (nonzero) digits is 162, while the sum is 19.

The square root of 31690 is about 178.0168531348. The cubic root of 31690 is about 31.6451685418.

It can be divided in two parts, 316 and 90, that added together give a triangular number (406 = T₂₈).

The spelling of 31690 in words is "thirty-one thousand, six hundred ninety".