64436813 has 6 divisors (see below), whose sum is σ = 74957166. Its totient is φ = 55231512.

The previous prime is 64436807. The next prime is 64436821. The reversal of 64436813 is 31863446.

It can be written as a sum of positive squares in only one way, i.e., 50879689 + 13557124 = 7133^2 + 3682^2 .

It is not a de Polignac number, because 64436813 - 2¹² = 64432717 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 (64436803) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 657470 + ... + 657567.

It is an arithmetic number, because the mean of its divisors is an integer number (12492861).

Almost surely, 2^64436813 is an apocalyptic number.

It is an amenable number.

64436813 is a deficient number, since it is larger than the sum of its proper divisors (10520353).

64436813 is a wasteful number, since it uses less digits than its factorization.

64436813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1315051 (or 1315044 counting only the distinct ones).

The product of its digits is 41472, while the sum is 35.

The square root of 64436813 is about 8027.2543873980. The cubic root of 64436813 is about 400.9079645250.

The spelling of 64436813 in words is "sixty-four million, four hundred thirty-six thousand, eight hundred thirteen".