31436681 has 4 divisors (see below), whose sum is σ = 31492500. Its totient is φ = 31380864.

The previous prime is 31436677. The next prime is 31436683. The reversal of 31436681 is 18663413.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18663413 = 173 ⋅107881.

It can be written as a sum of positive squares in 2 ways, for example, as 13075456 + 18361225 = 3616^2 + 4285^2 .

It is a cyclic number.

It is not a de Polignac number, because 31436681 - 2² = 31436677 is a prime.

It is a super-2 number, since 2×31436681² = 1976529824591522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31436683) 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, 27056 + ... + 28193.

It is an arithmetic number, because the mean of its divisors is an integer number (7873125).

Almost surely, 2^31436681 is an apocalyptic number.

It is an amenable number.

31436681 is a deficient number, since it is larger than the sum of its proper divisors (55819).

31436681 is an equidigital number, since it uses as much as digits as its factorization.

31436681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55818.

The product of its digits is 10368, while the sum is 32.

The square root of 31436681 is about 5606.8423377156. The cubic root of 31436681 is about 315.6062265212.

The spelling of 31436681 in words is "thirty-one million, four hundred thirty-six thousand, six hundred eighty-one".