64131985 has 4 divisors (see below), whose sum is σ = 76958388. Its totient is φ = 51305584.

The previous prime is 64131983. The next prime is 64132031. The reversal of 64131985 is 58913146.

64131985 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39450961 + 24681024 = 6281^2 + 4968^2 .

It is a cyclic number.

It is not a de Polignac number, because 64131985 - 2¹ = 64131983 is a prime.

It is a super-2 number, since 2×64131985² = 8225823000080450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64131983) 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 3 ways as a sum of consecutive naturals, for example, 6413194 + ... + 6413203.

It is an arithmetic number, because the mean of its divisors is an integer number (19239597).

Almost surely, 2^64131985 is an apocalyptic number.

It is an amenable number.

64131985 is a deficient number, since it is larger than the sum of its proper divisors (12826403).

64131985 is a wasteful number, since it uses less digits than its factorization.

64131985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12826402.

The product of its digits is 25920, while the sum is 37.

The square root of 64131985 is about 8008.2448139402. The cubic root of 64131985 is about 400.2747799467.

The spelling of 64131985 in words is "sixty-four million, one hundred thirty-one thousand, nine hundred eighty-five".