1666065600 has 504 divisors, whose sum is σ = 6301404720. Its totient is φ = 416931840.

The previous prime is 1666065593. The next prime is 1666065607. The reversal of 1666065600 is 65606661.

It is an interprime number because it is at equal distance from previous prime (1666065593) and next prime (1666065607).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666065607) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 28238371 + ... + 28238429.

Almost surely, 2^1666065600 is an apocalyptic number.

1666065600 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 1666065600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3150702360).

1666065600 is an abundant number, since it is smaller than the sum of its proper divisors (4635339120).

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

1666065600 is a wasteful number, since it uses less digits than its factorization.

1666065600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 1666065600 is about 40817.4668493771. The cubic root of 1666065600 is about 1185.4885556926.

The spelling of 1666065600 in words is "one billion, six hundred sixty-six million, sixty-five thousand, six hundred".