64231645 has 4 divisors (see below), whose sum is σ = 77077980. Its totient is φ = 51385312.

The previous prime is 64231633. The next prime is 64231649. The reversal of 64231645 is 54613246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54613246 = 2 ⋅27306623.

It can be written as a sum of positive squares in 2 ways, for example, as 48818169 + 15413476 = 6987^2 + 3926^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64231645 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64231649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6423160 + ... + 6423169.

It is an arithmetic number, because the mean of its divisors is an integer number (19269495).

Almost surely, 2^64231645 is an apocalyptic number.

It is an amenable number.

64231645 is a deficient number, since it is larger than the sum of its proper divisors (12846335).

64231645 is a wasteful number, since it uses less digits than its factorization.

64231645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12846334.

The product of its digits is 17280, while the sum is 31.

The square root of 64231645 is about 8014.4647357138. The cubic root of 64231645 is about 400.4820126761.

The spelling of 64231645 in words is "sixty-four million, two hundred thirty-one thousand, six hundred forty-five".