840577609 has 2 divisors, whose sum is σ = 840577610. Its totient is φ = 840577608.

The previous prime is 840577607. The next prime is 840577643. The reversal of 840577609 is 906775048.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 669360384 + 171217225 = 25872^2 + 13085^2 .

It is a cyclic number.

It is not a de Polignac number, because 840577609 - 2¹ = 840577607 is a prime.

Together with 840577607, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (840577601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420288804 + 420288805.

It is an arithmetic number, because the mean of its divisors is an integer number (420288805).

Almost surely, 2^840577609 is an apocalyptic number.

It is an amenable number.

840577609 is a deficient number, since it is larger than the sum of its proper divisors (1).

840577609 is an equidigital number, since it uses as much as digits as its factorization.

840577609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 423360, while the sum is 46.

The square root of 840577609 is about 28992.7164819028. The cubic root of 840577609 is about 943.7550149639.

The spelling of 840577609 in words is "eight hundred forty million, five hundred seventy-seven thousand, six hundred nine".