666661593 has 16 divisors (see below), whose sum is σ = 962127936. Its totient is φ = 408166080.

The previous prime is 666661577. The next prime is 666661609. The reversal of 666661593 is 395166666.

It is an interprime number because it is at equal distance from previous prime (666661577) and next prime (666661609).

It is not a de Polignac number, because 666661593 - 2⁴ = 666661577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666661573) 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, 35703 + ... + 51068.

It is an arithmetic number, because the mean of its divisors is an integer number (60132996).

Almost surely, 2^666661593 is an apocalyptic number.

It is an amenable number.

666661593 is a deficient number, since it is larger than the sum of its proper divisors (295466343).

666661593 is a wasteful number, since it uses less digits than its factorization.

666661593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86984.

The product of its digits is 1049760, while the sum is 48.

The square root of 666661593 is about 25819.7907233967. The cubic root of 666661593 is about 873.5782486026.

The spelling of 666661593 in words is "six hundred sixty-six million, six hundred sixty-one thousand, five hundred ninety-three".