666225557 has 8 divisors (see below), whose sum is σ = 723912960. Its totient is φ = 610800480.

The previous prime is 666225509. The next prime is 666225559. The reversal of 666225557 is 755522666.

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 666225557 - 2²⁸ = 397790101 is a prime.

It is a super-4 number, since 4×666225557⁴ (a number of 36 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666225559) 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, 564968 + ... + 566145.

It is an arithmetic number, because the mean of its divisors is an integer number (90489120).

Almost surely, 2^666225557 is an apocalyptic number.

It is an amenable number.

666225557 is a deficient number, since it is larger than the sum of its proper divisors (57687403).

666225557 is a wasteful number, since it uses less digits than its factorization.

666225557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1131163.

The product of its digits is 756000, while the sum is 44.

The square root of 666225557 is about 25811.3455092911. The cubic root of 666225557 is about 873.3877498320.

The spelling of 666225557 in words is "six hundred sixty-six million, two hundred twenty-five thousand, five hundred fifty-seven".