64644923 has 4 divisors (see below), whose sum is σ = 73879920. Its totient is φ = 55409928.

The previous prime is 64644913. The next prime is 64644929. The reversal of 64644923 is 32944646.

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

It is not a de Polignac number, because 64644923 - 2¹⁰ = 64643899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64644929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4617488 + ... + 4617501.

It is an arithmetic number, because the mean of its divisors is an integer number (18469980).

Almost surely, 2^64644923 is an apocalyptic number.

64644923 is a deficient number, since it is larger than the sum of its proper divisors (9234997).

64644923 is an equidigital number, since it uses as much as digits as its factorization.

64644923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9234996.

The product of its digits is 124416, while the sum is 38.

The square root of 64644923 is about 8040.2066515731. The cubic root of 64644923 is about 401.3391015980.

The spelling of 64644923 in words is "sixty-four million, six hundred forty-four thousand, nine hundred twenty-three".