64640497 has 2 divisors, whose sum is σ = 64640498. Its totient is φ = 64640496.

The previous prime is 64640473. The next prime is 64640501. The reversal of 64640497 is 79404646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60078001 + 4562496 = 7751^2 + 2136^2 .

It is a cyclic number.

It is not a de Polignac number, because 64640497 - 2¹¹ = 64638449 is a prime.

It is not a weakly prime, because it can be changed into another prime (64640437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32320248 + 32320249.

It is an arithmetic number, because the mean of its divisors is an integer number (32320249).

Almost surely, 2^64640497 is an apocalyptic number.

It is an amenable number.

64640497 is a deficient number, since it is larger than the sum of its proper divisors (1).

64640497 is an equidigital number, since it uses as much as digits as its factorization.

64640497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 40.

The square root of 64640497 is about 8039.9314051800. The cubic root of 64640497 is about 401.3299419851.

The spelling of 64640497 in words is "sixty-four million, six hundred forty thousand, four hundred ninety-seven".