64697209 has 2 divisors, whose sum is σ = 64697210. Its totient is φ = 64697208.

The previous prime is 64697203. The next prime is 64697219. The reversal of 64697209 is 90279646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61669609 + 3027600 = 7853^2 + 1740^2 .

It is a cyclic number.

It is not a de Polignac number, because 64697209 - 2⁵ = 64697177 is a prime.

It is not a weakly prime, because it can be changed into another prime (64697203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32348604 + 32348605.

It is an arithmetic number, because the mean of its divisors is an integer number (32348605).

Almost surely, 2^64697209 is an apocalyptic number.

It is an amenable number.

64697209 is a deficient number, since it is larger than the sum of its proper divisors (1).

64697209 is an equidigital number, since it uses as much as digits as its factorization.

64697209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 64697209 is about 8043.4575277054. The cubic root of 64697209 is about 401.4472759155.

The spelling of 64697209 in words is "sixty-four million, six hundred ninety-seven thousand, two hundred nine".