840732257 has 2 divisors, whose sum is σ = 840732258. Its totient is φ = 840732256.

The previous prime is 840732203. The next prime is 840732283. The reversal of 840732257 is 752237048.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 666465856 + 174266401 = 25816^2 + 13201^2 .

It is a cyclic number.

It is not a de Polignac number, because 840732257 - 2²⁰ = 839683681 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 840732257.

It is not a weakly prime, because it can be changed into another prime (840732157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420366128 + 420366129.

It is an arithmetic number, because the mean of its divisors is an integer number (420366129).

Almost surely, 2^840732257 is an apocalyptic number.

It is an amenable number.

840732257 is a deficient number, since it is larger than the sum of its proper divisors (1).

840732257 is an equidigital number, since it uses as much as digits as its factorization.

840732257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 94080, while the sum is 38.

The square root of 840732257 is about 28995.3833739097. The cubic root of 840732257 is about 943.8128882146.

The spelling of 840732257 in words is "eight hundred forty million, seven hundred thirty-two thousand, two hundred fifty-seven".