666665055 has 24 divisors (see below), whose sum is σ = 1320632352. Its totient is φ = 304761024.

The previous prime is 666665033. The next prime is 666665057. The reversal of 666665055 is 550566666.

It is not a de Polignac number, because 666665055 - 2¹² = 666660959 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 666665055.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666665057) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1057884 + ... + 1058513.

It is an arithmetic number, because the mean of its divisors is an integer number (55026348).

Almost surely, 2^666665055 is an apocalyptic number.

666665055 is a deficient number, since it is larger than the sum of its proper divisors (653967297).

666665055 is a wasteful number, since it uses less digits than its factorization.

666665055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2116415 (or 2116412 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 45.

The square root of 666665055 is about 25819.8577649065. The cubic root of 666665055 is about 873.5797607755.

The spelling of 666665055 in words is "six hundred sixty-six million, six hundred sixty-five thousand, fifty-five".