64631605 has 4 divisors (see below), whose sum is σ = 77557932. Its totient is φ = 51705280.

The previous prime is 64631599. The next prime is 64631653. The reversal of 64631605 is 50613646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50613646 = 2 ⋅25306823.

It can be written as a sum of positive squares in 2 ways, for example, as 22667121 + 41964484 = 4761^2 + 6478^2 .

It is not a de Polignac number, because 64631605 - 2⁷ = 64631477 is a prime.

It is a super-3 number, since 3×64631605³ (a number of 24 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6463156 + ... + 6463165.

It is an arithmetic number, because the mean of its divisors is an integer number (19389483).

Almost surely, 2^64631605 is an apocalyptic number.

It is an amenable number.

64631605 is a deficient number, since it is larger than the sum of its proper divisors (12926327).

64631605 is a wasteful number, since it uses less digits than its factorization.

64631605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12926326.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 64631605 is about 8039.3783963687. The cubic root of 64631605 is about 401.3115387154.

The spelling of 64631605 in words is "sixty-four million, six hundred thirty-one thousand, six hundred five".