840761649 has 108 divisors (see below), whose sum is σ = 1586555100. Its totient is φ = 427085568.

The previous prime is 840761617. The next prime is 840761651. The reversal of 840761649 is 946167048.

It can be written as a sum of positive squares in 6 ways, for example, as 205721649 + 635040000 = 14343^2 + 25200^2 .

It is not a de Polignac number, because 840761649 - 2⁵ = 840761617 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (840761689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 2161147 + ... + 2161535.

It is an arithmetic number, because the mean of its divisors is an integer number (14690325).

Almost surely, 2^840761649 is an apocalyptic number.

It is an amenable number.

840761649 is a deficient number, since it is larger than the sum of its proper divisors (745793451).

840761649 is a wasteful number, since it uses less digits than its factorization.

840761649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464 (or 441 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 840761649 is about 28995.8902087865. The cubic root of 840761649 is about 943.8238866527.

The spelling of 840761649 in words is "eight hundred forty million, seven hundred sixty-one thousand, six hundred forty-nine".