1666610400 has 432 divisors, whose sum is σ = 6724819584. Its totient is φ = 351037440.

The previous prime is 1666610399. The next prime is 1666610501. The reversal of 1666610400 is 40166661.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 2838907 + ... + 2839493.

It is an arithmetic number, because the mean of its divisors is an integer number (15566712).

Almost surely, 2^1666610400 is an apocalyptic number.

1666610400 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 1666610400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3362409792).

1666610400 is an abundant number, since it is smaller than the sum of its proper divisors (5058209184).

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

1666610400 is a wasteful number, since it uses less digits than its factorization.

1666610400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 617 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 1666610400 is about 40824.1399174557. The cubic root of 1666610400 is about 1185.6177590445.

The spelling of 1666610400 in words is "one billion, six hundred sixty-six million, six hundred ten thousand, four hundred".