666273600 has 420 divisors, whose sum is σ = 2520987084. Its totient is φ = 172523520.

The previous prime is 666273599. The next prime is 666273611. The reversal of 666273600 is 6372666.

It can be written as a sum of positive squares in 6 ways, for example, as 1871424 + 664402176 = 1368^2 + 25776^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 6868752 + ... + 6868848.

Almost surely, 2^666273600 is an apocalyptic number.

666273600 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 666273600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1260493542).

666273600 is an abundant number, since it is smaller than the sum of its proper divisors (1854713484).

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

666273600 is a wasteful number, since it uses less digits than its factorization.

666273600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184 (or 160 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 36.

The square root of 666273600 is about 25812.2761491504. The cubic root of 666273600 is about 873.4087433022.

The spelling of 666273600 in words is "six hundred sixty-six million, two hundred seventy-three thousand, six hundred".