840420872 has 8 divisors (see below), whose sum is σ = 1575789150. Its totient is φ = 420210432.

The previous prime is 840420871. The next prime is 840420877. The reversal of 840420872 is 278024048.

It can be written as a sum of positive squares in only one way, i.e., 712142596 + 128278276 = 26686^2 + 11326^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (840420871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52526297 + ... + 52526312.

Almost surely, 2^840420872 is an apocalyptic number.

It is an amenable number.

840420872 is a deficient number, since it is larger than the sum of its proper divisors (735368278).

840420872 is a wasteful number, since it uses less digits than its factorization.

840420872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105052615 (or 105052611 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 35.

The square root of 840420872 is about 28990.0133149331. The cubic root of 840420872 is about 943.6963527127.

The spelling of 840420872 in words is "eight hundred forty million, four hundred twenty thousand, eight hundred seventy-two".