64840109 has 2 divisors, whose sum is σ = 64840110. Its totient is φ = 64840108.

The previous prime is 64840093. The next prime is 64840123. The reversal of 64840109 is 90104846.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64048009 + 792100 = 8003^2 + 890^2 .

It is a cyclic number.

It is not a de Polignac number, because 64840109 - 2⁴ = 64840093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64840129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32420054 + 32420055.

It is an arithmetic number, because the mean of its divisors is an integer number (32420055).

Almost surely, 2^64840109 is an apocalyptic number.

It is an amenable number.

64840109 is a deficient number, since it is larger than the sum of its proper divisors (1).

64840109 is an equidigital number, since it uses as much as digits as its factorization.

64840109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 64840109 is about 8052.3356239044. The cubic root of 64840109 is about 401.7426242107.

The spelling of 64840109 in words is "sixty-four million, eight hundred forty thousand, one hundred nine".