1666155516 has 96 divisors (see below), whose sum is σ = 4209408000. Its totient is φ = 512783104.

The previous prime is 1666155497. The next prime is 1666155521. The reversal of 1666155516 is 6155516661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3478165 + ... + 3478643.

It is an arithmetic number, because the mean of its divisors is an integer number (43848000).

Almost surely, 2^1666155516 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666155516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2104704000).

1666155516 is an abundant number, since it is smaller than the sum of its proper divisors (2543252484).

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

1666155516 is a wasteful number, since it uses less digits than its factorization.

1666155516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 596 (or 560 counting only the distinct ones).

The product of its digits is 162000, while the sum is 42.

The square root of 1666155516 is about 40818.5682747448. The cubic root of 1666155516 is about 1185.5098818780.

The spelling of 1666155516 in words is "one billion, six hundred sixty-six million, one hundred fifty-five thousand, five hundred sixteen".