666455540 has 24 divisors (see below), whose sum is σ = 1400428680. Its totient is φ = 266416128.

The previous prime is 666455519. The next prime is 666455593. The reversal of 666455540 is 45554666.

It can be written as a sum of positive squares in 4 ways, for example, as 26770276 + 639685264 = 5174^2 + 25292^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25556 + ... + 44564.

It is an arithmetic number, because the mean of its divisors is an integer number (58351195).

Almost surely, 2^666455540 is an apocalyptic number.

It is an amenable number.

666455540 is an abundant number, since it is smaller than the sum of its proper divisors (733973140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666455540 is a wasteful number, since it uses less digits than its factorization.

666455540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20771 (or 20769 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 41.

The square root of 666455540 is about 25815.8002006523. The cubic root of 666455540 is about 873.4882369339.

The spelling of 666455540 in words is "six hundred sixty-six million, four hundred fifty-five thousand, five hundred forty".