666694800 has 360 divisors, whose sum is σ = 2532580960. Its totient is φ = 168428160.

The previous prime is 666694793. The next prime is 666694843. The reversal of 666694800 is 8496666.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is a tau number, because it is divible by the number of its divisors (360).

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

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, 35089191 + ... + 35089209.

Almost surely, 2^666694800 is an apocalyptic number.

666694800 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 666694800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1266290480).

666694800 is an abundant number, since it is smaller than the sum of its proper divisors (1865886160).

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

666694800 is an equidigital number, since it uses as much as digits as its factorization.

666694800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 29 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 666694800 is about 25820.4337686260. The cubic root of 666694800 is about 873.5927529287.

The spelling of 666694800 in words is "six hundred sixty-six million, six hundred ninety-four thousand, eight hundred".