840678901 has 2 divisors, whose sum is σ = 840678902. Its totient is φ = 840678900.

The previous prime is 840678899. The next prime is 840678931. The reversal of 840678901 is 109876048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 766736100 + 73942801 = 27690^2 + 8599^2 .

It is a cyclic number.

It is not a de Polignac number, because 840678901 - 2¹ = 840678899 is a prime.

Together with 840678899, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840678931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420339450 + 420339451.

It is an arithmetic number, because the mean of its divisors is an integer number (420339451).

Almost surely, 2^840678901 is an apocalyptic number.

It is an amenable number.

840678901 is a deficient number, since it is larger than the sum of its proper divisors (1).

840678901 is an equidigital number, since it uses as much as digits as its factorization.

840678901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96768, while the sum is 43.

The square root of 840678901 is about 28994.4632818061. The cubic root of 840678901 is about 943.7929218319.

The spelling of 840678901 in words is "eight hundred forty million, six hundred seventy-eight thousand, nine hundred one".