161861616 has 120 divisors (see below), whose sum is σ = 523061760. Its totient is φ = 45767808.

The previous prime is 161861591. The next prime is 161861647. The reversal of 161861616 is 616168161.

161861616 is a `hidden beast` number, since 16 + 18 + 616 + 16 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

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, 103045 + ... + 104603.

It is an arithmetic number, because the mean of its divisors is an integer number (4358848).

Almost surely, 2^161861616 is an apocalyptic number.

161861616 is a gapful number since it is divisible by the number (16) 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 161861616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261530880).

161861616 is an abundant number, since it is smaller than the sum of its proper divisors (361200144).

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

161861616 is a wasteful number, since it uses less digits than its factorization.

161861616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1683 (or 1674 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 161861616 is about 12722.4846629894. The cubic root of 161861616 is about 544.9809111514.

The spelling of 161861616 in words is "one hundred sixty-one million, eight hundred sixty-one thousand, six hundred sixteen".