666478365 has 32 divisors (see below), whose sum is σ = 1234145280. Its totient is φ = 300815424.

The previous prime is 666478361. The next prime is 666478399. The reversal of 666478365 is 563874666.

It is not a de Polignac number, because 666478365 - 2² = 666478361 is a prime.

It is a super-2 number, since 2×666478365² = 888386822026146450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666478361) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31879 + ... + 48468.

It is an arithmetic number, because the mean of its divisors is an integer number (38567040).

Almost surely, 2^666478365 is an apocalyptic number.

It is an amenable number.

666478365 is a deficient number, since it is larger than the sum of its proper divisors (567666915).

666478365 is a wasteful number, since it uses less digits than its factorization.

666478365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80441.

The product of its digits is 4354560, while the sum is 51.

The square root of 666478365 is about 25816.2422710975. The cubic root of 666478365 is about 873.4982086626.

The spelling of 666478365 in words is "six hundred sixty-six million, four hundred seventy-eight thousand, three hundred sixty-five".