1666165550 has 48 divisors (see below), whose sum is σ = 3556668192. Its totient is φ = 568857600.

The previous prime is 1666165549. The next prime is 1666165577. The reversal of 1666165550 is 555616661.

It is a super-2 number, since 2×1666165550² = 5552215280013605000, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1666165498 and 1666165507.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74474 + ... + 94226.

It is an arithmetic number, because the mean of its divisors is an integer number (74097254).

Almost surely, 2^1666165550 is an apocalyptic number.

1666165550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1666165550 is an abundant number, since it is smaller than the sum of its proper divisors (1890502642).

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

1666165550 is a wasteful number, since it uses less digits than its factorization.

1666165550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20013 (or 20008 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 41.

The square root of 1666165550 is about 40818.6911843092. The cubic root of 1666165550 is about 1185.5122616843.

The spelling of 1666165550 in words is "one billion, six hundred sixty-six million, one hundred sixty-five thousand, five hundred fifty".