666968400 has 540 divisors, whose sum is σ = 2848404000. Its totient is φ = 143700480.

The previous prime is 666968389. The next prime is 666968413. The reversal of 666968400 is 4869666.

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 3351501 + ... + 3351699.

Almost surely, 2^666968400 is an apocalyptic number.

666968400 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 666968400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1424202000).

666968400 is an abundant number, since it is smaller than the sum of its proper divisors (2181435600).

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

666968400 is a wasteful number, since it uses less digits than its factorization.

666968400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256 (or 235 counting only the distinct ones).

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

The square root of 666968400 is about 25825.7313546006. The cubic root of 666968400 is about 873.7122390307.

The spelling of 666968400 in words is "six hundred sixty-six million, nine hundred sixty-eight thousand, four hundred".