667878555 has 16 divisors (see below), whose sum is σ = 1105454880. Its totient is φ = 343918848.

The previous prime is 667878553. The next prime is 667878571. The reversal of 667878555 is 555878766.

667878555 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 667878555 - 2¹ = 667878553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 667878495 and 667878504.

It is not an unprimeable number, because it can be changed into a prime (667878553) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 767242 + ... + 768111.

It is an arithmetic number, because the mean of its divisors is an integer number (69090930).

Almost surely, 2^667878555 is an apocalyptic number.

667878555 is a deficient number, since it is larger than the sum of its proper divisors (437576325).

667878555 is a wasteful number, since it uses less digits than its factorization.

667878555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1535390.

The product of its digits is 14112000, while the sum is 57.

The square root of 667878555 is about 25843.3464357850. The cubic root of 667878555 is about 874.1094852955.

The spelling of 667878555 in words is "six hundred sixty-seven million, eight hundred seventy-eight thousand, five hundred fifty-five".