840644806 has 4 divisors (see below), whose sum is σ = 1260967212. Its totient is φ = 420322402.

The previous prime is 840644789. The next prime is 840644807. The reversal of 840644806 is 608446048.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840644807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210161200 + ... + 210161203.

It is an arithmetic number, because the mean of its divisors is an integer number (315241803).

Almost surely, 2^840644806 is an apocalyptic number.

840644806 is a deficient number, since it is larger than the sum of its proper divisors (420322406).

840644806 is a wasteful number, since it uses less digits than its factorization.

840644806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420322405.

The product of its (nonzero) digits is 147456, while the sum is 40.

The square root of 840644806 is about 28993.8753187634. The cubic root of 840644806 is about 943.7801626779.

The spelling of 840644806 in words is "eight hundred forty million, six hundred forty-four thousand, eight hundred six".