64688511997 has 2 divisors, whose sum is σ = 64688511998. Its totient is φ = 64688511996.

The previous prime is 64688511971. The next prime is 64688512003. The reversal of 64688511997 is 79911588646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61091031556 + 3597480441 = 247166^2 + 59979^2 .

It is a cyclic number.

It is not a de Polignac number, because 64688511997 - 2²⁷ = 64554294269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64688511907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32344255998 + 32344255999.

It is an arithmetic number, because the mean of its divisors is an integer number (32344255999).

Almost surely, 2^64688511997 is an apocalyptic number.

It is an amenable number.

64688511997 is a deficient number, since it is larger than the sum of its proper divisors (1).

64688511997 is an equidigital number, since it uses as much as digits as its factorization.

64688511997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26127360, while the sum is 64.

The spelling of 64688511997 in words is "sixty-four billion, six hundred eighty-eight million, five hundred eleven thousand, nine hundred ninety-seven".