666199800 has 288 divisors, whose sum is σ = 2627882400. Its totient is φ = 148055040.

The previous prime is 666199759. The next prime is 666199823. The reversal of 666199800 is 8991666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 465486 + ... + 466914.

Almost surely, 2^666199800 is an apocalyptic number.

666199800 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666199800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1313941200).

666199800 is an abundant number, since it is smaller than the sum of its proper divisors (1961682600).

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

666199800 is a wasteful number, since it uses less digits than its factorization.

666199800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1495 (or 1483 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 666199800 is about 25810.8465572131. The cubic root of 666199800 is about 873.3764943156.

The spelling of 666199800 in words is "six hundred sixty-six million, one hundred ninety-nine thousand, eight hundred".