31638065 has 4 divisors (see below), whose sum is σ = 37965684. Its totient is φ = 25310448.

The previous prime is 31638053. The next prime is 31638083. The reversal of 31638065 is 56083613.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56083613 = 41 ⋅1367893.

It can be written as a sum of positive squares in 2 ways, for example, as 16459249 + 15178816 = 4057^2 + 3896^2 .

It is a cyclic number.

It is not a de Polignac number, because 31638065 - 2⁴ = 31638049 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3163802 + ... + 3163811.

It is an arithmetic number, because the mean of its divisors is an integer number (9491421).

Almost surely, 2^31638065 is an apocalyptic number.

It is an amenable number.

31638065 is a deficient number, since it is larger than the sum of its proper divisors (6327619).

31638065 is an equidigital number, since it uses as much as digits as its factorization.

31638065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6327618.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 31638065 is about 5624.7724398415. The cubic root of 31638065 is about 316.2787191341.

The spelling of 31638065 in words is "thirty-one million, six hundred thirty-eight thousand, sixty-five".