1666258560 has 256 divisors, whose sum is σ = 5942275200. Its totient is φ = 441262080.

The previous prime is 1666258547. The next prime is 1666258579. The reversal of 1666258560 is 658526661.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 31 ways as a sum of consecutive naturals, for example, 3645852 + ... + 3646308.

Almost surely, 2^1666258560 is an apocalyptic number.

1666258560 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 1666258560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2971137600).

1666258560 is an abundant number, since it is smaller than the sum of its proper divisors (4276016640).

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

1666258560 is a wasteful number, since it uses less digits than its factorization.

1666258560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696 (or 678 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The square root of 1666258560 is about 40819.8304749052. The cubic root of 1666258560 is about 1185.5343208055.

The spelling of 1666258560 in words is "one billion, six hundred sixty-six million, two hundred fifty-eight thousand, five hundred sixty".