161986860 has 144 divisors (see below), whose sum is σ = 571334400. Its totient is φ = 36381312.

The previous prime is 161986841. The next prime is 161986883. The reversal of 161986860 is 68689161.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 73251 + ... + 75429.

It is an arithmetic number, because the mean of its divisors is an integer number (3967600).

Almost surely, 2^161986860 is an apocalyptic number.

161986860 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 161986860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (285667200).

161986860 is an abundant number, since it is smaller than the sum of its proper divisors (409347540).

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

161986860 is a wasteful number, since it uses less digits than its factorization.

161986860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2260 (or 2255 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 161986860 is about 12727.4058629400. The cubic root of 161986860 is about 545.1214385841.

The spelling of 161986860 in words is "one hundred sixty-one million, nine hundred eighty-six thousand, eight hundred sixty".