1661508860 has 48 divisors (see below), whose sum is σ = 3929167872. Its totient is φ = 584692800.

The previous prime is 1661508851. The next prime is 1661508881. The reversal of 1661508860 is 688051661.

It is a happy number.

It is a super-2 number, since 2×1661508860² = 5521223383716999200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 114992 + ... + 128631.

It is an arithmetic number, because the mean of its divisors is an integer number (81857664).

Almost surely, 2^1661508860 is an apocalyptic number.

1661508860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661508860 is an abundant number, since it is smaller than the sum of its proper divisors (2267659012).

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

1661508860 is a wasteful number, since it uses less digits than its factorization.

1661508860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243674 (or 243672 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 41.

The square root of 1661508860 is about 40761.6101252146. The cubic root of 1661508860 is about 1184.4067864709.

The spelling of 1661508860 in words is "one billion, six hundred sixty-one million, five hundred eight thousand, eight hundred sixty".