64531865 has 8 divisors (see below), whose sum is σ = 77494920. Its totient is φ = 51587712.

The previous prime is 64531843. The next prime is 64531871. The reversal of 64531865 is 56813546.

It can be written as a sum of positive squares in 4 ways, for example, as 4748041 + 59783824 = 2179^2 + 7732^2 .

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 64531865 - 2²² = 60337561 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4391 + ... + 12179.

It is an arithmetic number, because the mean of its divisors is an integer number (9686865).

Almost surely, 2^64531865 is an apocalyptic number.

It is an amenable number.

64531865 is a deficient number, since it is larger than the sum of its proper divisors (12963055).

64531865 is a wasteful number, since it uses less digits than its factorization.

64531865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9451.

The product of its digits is 86400, while the sum is 38.

The square root of 64531865 is about 8033.1727853943. The cubic root of 64531865 is about 401.1049967280.

The spelling of 64531865 in words is "sixty-four million, five hundred thirty-one thousand, eight hundred sixty-five".