1638656855 has 32 divisors (see below), whose sum is σ = 2214362880. Its totient is φ = 1153912320.

The previous prime is 1638656849. The next prime is 1638656897. The reversal of 1638656855 is 5586568361.

It is not a de Polignac number, because 1638656855 - 2⁶ = 1638656791 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1638656797 and 1638656806.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 213647 + ... + 221183.

It is an arithmetic number, because the mean of its divisors is an integer number (69198840).

Almost surely, 2^1638656855 is an apocalyptic number.

1638656855 is a deficient number, since it is larger than the sum of its proper divisors (575706025).

1638656855 is a wasteful number, since it uses less digits than its factorization.

1638656855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7679.

The product of its digits is 5184000, while the sum is 53.

The square root of 1638656855 is about 40480.3267649855. The cubic root of 1638656855 is about 1178.9516819390.

The spelling of 1638656855 in words is "one billion, six hundred thirty-eight million, six hundred fifty-six thousand, eight hundred fifty-five".