161856870 has 96 divisors (see below), whose sum is σ = 457083648. Its totient is φ = 35932032.

The previous prime is 161856857. The next prime is 161856887. The reversal of 161856870 is 78658161.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 287209 + ... + 287771.

It is an arithmetic number, because the mean of its divisors is an integer number (4761288).

Almost surely, 2^161856870 is an apocalyptic number.

161856870 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 161856870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (228541824).

161856870 is an abundant number, since it is smaller than the sum of its proper divisors (295226778).

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

161856870 is a wasteful number, since it uses less digits than its factorization.

161856870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 654 (or 617 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 42.

The square root of 161856870 is about 12722.2981414523. The cubic root of 161856870 is about 544.9755845752.

The spelling of 161856870 in words is "one hundred sixty-one million, eight hundred fifty-six thousand, eight hundred seventy".