64968561 has 30 divisors (see below), whose sum is σ = 112903890. Its totient is φ = 37122624.

The previous prime is 64968557. The next prime is 64968569. The reversal of 64968561 is 16586946.

It can be written as a sum of positive squares in only one way, i.e., 50680161 + 14288400 = 7119^2 + 3780^2 .

It is not a de Polignac number, because 64968561 - 2² = 64968557 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64968569) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 4216 + ... + 12153.

It is an arithmetic number, because the mean of its divisors is an integer number (3763463).

Almost surely, 2^64968561 is an apocalyptic number.

It is an amenable number.

64968561 is a deficient number, since it is larger than the sum of its proper divisors (47935329).

64968561 is a wasteful number, since it uses less digits than its factorization.

64968561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16395 (or 16379 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The square root of 64968561 is about 8060.3077484672. The cubic root of 64968561 is about 402.0077409960.

The spelling of 64968561 in words is "sixty-four million, nine hundred sixty-eight thousand, five hundred sixty-one".