64939561 has 2 divisors, whose sum is σ = 64939562. Its totient is φ = 64939560.

The previous prime is 64939519. The next prime is 64939573. The reversal of 64939561 is 16593946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58614336 + 6325225 = 7656^2 + 2515^2 .

It is a cyclic number.

It is not a de Polignac number, because 64939561 - 2¹⁷ = 64808489 is a prime.

It is not a weakly prime, because it can be changed into another prime (64939661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32469780 + 32469781.

It is an arithmetic number, because the mean of its divisors is an integer number (32469781).

Almost surely, 2^64939561 is an apocalyptic number.

It is an amenable number.

64939561 is a deficient number, since it is larger than the sum of its proper divisors (1).

64939561 is an equidigital number, since it uses as much as digits as its factorization.

64939561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 174960, while the sum is 43.

The square root of 64939561 is about 8058.5086089177. The cubic root of 64939561 is about 401.9479173963.

The spelling of 64939561 in words is "sixty-four million, nine hundred thirty-nine thousand, five hundred sixty-one".