64673813 has 4 divisors (see below), whose sum is σ = 64690188. Its totient is φ = 64657440.

The previous prime is 64673779. The next prime is 64673837. The reversal of 64673813 is 31837646.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1582564 + 63091249 = 1258^2 + 7943^2 .

It is a cyclic number.

It is not a de Polignac number, because 64673813 - 2¹⁴ = 64657429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64673863) 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, 1793 + ... + 11513.

It is an arithmetic number, because the mean of its divisors is an integer number (16172547).

Almost surely, 2^64673813 is an apocalyptic number.

It is an amenable number.

64673813 is a deficient number, since it is larger than the sum of its proper divisors (16375).

64673813 is an equidigital number, since it uses as much as digits as its factorization.

64673813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16374.

The product of its digits is 72576, while the sum is 38.

The square root of 64673813 is about 8042.0030465053. The cubic root of 64673813 is about 401.3988792227.

The spelling of 64673813 in words is "sixty-four million, six hundred seventy-three thousand, eight hundred thirteen".