64672661 has 2 divisors, whose sum is σ = 64672662. Its totient is φ = 64672660.

The previous prime is 64672609. The next prime is 64672679. The reversal of 64672661 is 16627646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43970161 + 20702500 = 6631^2 + 4550^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64672661 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64672681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32336330 + 32336331.

It is an arithmetic number, because the mean of its divisors is an integer number (32336331).

Almost surely, 2^64672661 is an apocalyptic number.

It is an amenable number.

64672661 is a deficient number, since it is larger than the sum of its proper divisors (1).

64672661 is an equidigital number, since it uses as much as digits as its factorization.

64672661 is an evil number, because the sum of its binary digits is even.

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

The square root of 64672661 is about 8041.9314222393. The cubic root of 64672661 is about 401.3964959074.

The spelling of 64672661 in words is "sixty-four million, six hundred seventy-two thousand, six hundred sixty-one".