840499681 has 4 divisors (see below), whose sum is σ = 960571072. Its totient is φ = 720428292.

The previous prime is 840499661. The next prime is 840499697. The reversal of 840499681 is 186994048.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 840499681 - 2⁷ = 840499553 is a prime.

It is a super-2 number, since 2×840499681² = 1412879427522203522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (840499651) 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 3 ways as a sum of consecutive naturals, for example, 60035685 + ... + 60035698.

It is an arithmetic number, because the mean of its divisors is an integer number (240142768).

Almost surely, 2^840499681 is an apocalyptic number.

It is an amenable number.

840499681 is a deficient number, since it is larger than the sum of its proper divisors (120071391).

840499681 is a wasteful number, since it uses less digits than its factorization.

840499681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120071390.

The product of its (nonzero) digits is 497664, while the sum is 49.

The square root of 840499681 is about 28991.3725270122. The cubic root of 840499681 is about 943.7258496166.

The spelling of 840499681 in words is "eight hundred forty million, four hundred ninety-nine thousand, six hundred eighty-one".