666400206 has 16 divisors (see below), whose sum is σ = 1390748544. Its totient is φ = 212475384.

The previous prime is 666400181. The next prime is 666400223. The reversal of 666400206 is 602004666.

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, 2414356 + ... + 2414631.

It is an arithmetic number, because the mean of its divisors is an integer number (86921784).

Almost surely, 2^666400206 is an apocalyptic number.

666400206 is an abundant number, since it is smaller than the sum of its proper divisors (724348338).

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

666400206 is a wasteful number, since it uses less digits than its factorization.

666400206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4829015.

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 666400206 is about 25814.7284703907. The cubic root of 666400206 is about 873.4640618100.

The spelling of 666400206 in words is "six hundred sixty-six million, four hundred thousand, two hundred six".