840262309 has 2 divisors, whose sum is σ = 840262310. Its totient is φ = 840262308.

The previous prime is 840262277. The next prime is 840262391. The reversal of 840262309 is 903262048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 596434084 + 243828225 = 24422^2 + 15615^2 .

It is a cyclic number.

It is not a de Polignac number, because 840262309 - 2⁵ = 840262277 is a prime.

It is a super-2 number, since 2×840262309² = 1412081495852022962, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840262109) 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, 420131154 + 420131155.

It is an arithmetic number, because the mean of its divisors is an integer number (420131155).

Almost surely, 2^840262309 is an apocalyptic number.

It is an amenable number.

840262309 is a deficient number, since it is larger than the sum of its proper divisors (1).

840262309 is an equidigital number, since it uses as much as digits as its factorization.

840262309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 840262309 is about 28987.2783993255. The cubic root of 840262309 is about 943.6369996189.

The spelling of 840262309 in words is "eight hundred forty million, two hundred sixty-two thousand, three hundred nine".