666573551 has 8 divisors (see below), whose sum is σ = 764611584. Its totient is φ = 569238840.

The previous prime is 666573547. The next prime is 666573559. The reversal of 666573551 is 155375666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666573551 - 2² = 666573547 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666573559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 173795 + ... + 177588.

It is an arithmetic number, because the mean of its divisors is an integer number (95576448).

Almost surely, 2^666573551 is an apocalyptic number.

666573551 is a deficient number, since it is larger than the sum of its proper divisors (98038033).

666573551 is a wasteful number, since it uses less digits than its factorization.

666573551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351661.

The product of its digits is 567000, while the sum is 44.

The square root of 666573551 is about 25818.0857346163. The cubic root of 666573551 is about 873.5397908289.

The spelling of 666573551 in words is "six hundred sixty-six million, five hundred seventy-three thousand, five hundred fifty-one".