1666064400 has 960 divisors, whose sum is σ = 7646177280. Its totient is φ = 298598400.

The previous prime is 1666064383. The next prime is 1666064441. The reversal of 1666064400 is 44606661.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 22822764 + ... + 22822836.

It is an arithmetic number, because the mean of its divisors is an integer number (7964768).

Almost surely, 2^1666064400 is an apocalyptic number.

1666064400 is a gapful number since it is divisible by the number (10) 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 1666064400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3823088640).

1666064400 is an abundant number, since it is smaller than the sum of its proper divisors (5980112880).

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

1666064400 is a wasteful number, since it uses less digits than its factorization.

1666064400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 1666064400 is about 40817.4521497851. The cubic root of 1666064400 is about 1185.4882710726.

The spelling of 1666064400 in words is "one billion, six hundred sixty-six million, sixty-four thousand, four hundred".