64666081 has 2 divisors, whose sum is σ = 64666082. Its totient is φ = 64666080.

The previous prime is 64666033. The next prime is 64666097. The reversal of 64666081 is 18066646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63856081 + 810000 = 7991^2 + 900^2 .

It is a cyclic number.

It is not a de Polignac number, because 64666081 - 2¹³ = 64657889 is a prime.

It is a super-2 number, since 2×64666081² = 8363404063797122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64666081.

It is not a weakly prime, because it can be changed into another prime (64666681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32333040 + 32333041.

It is an arithmetic number, because the mean of its divisors is an integer number (32333041).

Almost surely, 2^64666081 is an apocalyptic number.

It is an amenable number.

64666081 is a deficient number, since it is larger than the sum of its proper divisors (1).

64666081 is an equidigital number, since it uses as much as digits as its factorization.

64666081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 64666081 is about 8041.5223061308. The cubic root of 64666081 is about 401.3828823316.

The spelling of 64666081 in words is "sixty-four million, six hundred sixty-six thousand, eighty-one".