667551555 has 36 divisors (see below), whose sum is σ = 1271852400. Its totient is φ = 323658720.

The previous prime is 667551553. The next prime is 667551559. The reversal of 667551555 is 555155766.

667551555 is a `hidden beast` number, since 66 + 75 + 515 + 5 + 5 = 666.

667551555 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 667551555 - 2¹ = 667551553 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 667551555.

It is not an unprimeable number, because it can be changed into a prime (667551553) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 55855 + ... + 66744.

Almost surely, 2^667551555 is an apocalyptic number.

667551555 is a deficient number, since it is larger than the sum of its proper divisors (604300845).

667551555 is a wasteful number, since it uses less digits than its factorization.

667551555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122632 (or 122618 counting only the distinct ones).

The product of its digits is 787500, while the sum is 45.

The square root of 667551555 is about 25837.0190811556. The cubic root of 667551555 is about 873.9668044337.

The spelling of 667551555 in words is "six hundred sixty-seven million, five hundred fifty-one thousand, five hundred fifty-five".