31640005 has 8 divisors (see below), whose sum is σ = 38160000. Its totient is φ = 25184016.

The previous prime is 31640003. The next prime is 31640017. The reversal of 31640005 is 50004613.

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

It is a cyclic number.

It is not a de Polignac number, because 31640005 - 2¹ = 31640003 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31640003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14905 + ... + 16894.

It is an arithmetic number, because the mean of its divisors is an integer number (4770000).

Almost surely, 2^31640005 is an apocalyptic number.

It is an amenable number.

31640005 is a deficient number, since it is larger than the sum of its proper divisors (6519995).

31640005 is a wasteful number, since it uses less digits than its factorization.

31640005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32003.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 31640005 is about 5624.9448886189. The cubic root of 31640005 is about 316.2851835853.

Adding to 31640005 its reverse (50004613), we get a palindrome (81644618).

The spelling of 31640005 in words is "thirty-one million, six hundred forty thousand, five".