840866656 has 36 divisors (see below), whose sum is σ = 1925738388. Its totient is φ = 360370752.

The previous prime is 840866647. The next prime is 840866671. The reversal of 840866656 is 656668048.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 266566 + ... + 269701.

It is an arithmetic number, because the mean of its divisors is an integer number (53492733).

Almost surely, 2^840866656 is an apocalyptic number.

It is an amenable number.

840866656 is an abundant number, since it is smaller than the sum of its proper divisors (1084871732).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

840866656 is a wasteful number, since it uses less digits than its factorization.

840866656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536291 (or 536276 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 49.

The square root of 840866656 is about 28997.7008743797. The cubic root of 840866656 is about 943.8631780060.

The spelling of 840866656 in words is "eight hundred forty million, eight hundred sixty-six thousand, six hundred fifty-six".