666698540 has 48 divisors (see below), whose sum is σ = 1438111584. Its totient is φ = 259468800.

The previous prime is 666698533. The next prime is 666698573. The reversal of 666698540 is 45896666.

666698540 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 382070 + ... + 383810.

It is an arithmetic number, because the mean of its divisors is an integer number (29960658).

Almost surely, 2^666698540 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666698540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (719055792).

666698540 is an abundant number, since it is smaller than the sum of its proper divisors (771413044).

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

666698540 is a wasteful number, since it uses less digits than its factorization.

666698540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2258 (or 2256 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 50.

The square root of 666698540 is about 25820.5061917849. The cubic root of 666698540 is about 873.5943864751.

The spelling of 666698540 in words is "six hundred sixty-six million, six hundred ninety-eight thousand, five hundred forty".