161209116 has 72 divisors (see below), whose sum is σ = 441028224. Its totient is φ = 51392880.

The previous prime is 161209073. The next prime is 161209117. The reversal of 161209116 is 611902161.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 161209116.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161209117) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18751 + ... + 25961.

It is an arithmetic number, because the mean of its divisors is an integer number (6125392).

Almost surely, 2^161209116 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161209116, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (220514112).

161209116 is an abundant number, since it is smaller than the sum of its proper divisors (279819108).

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

161209116 is a wasteful number, since it uses less digits than its factorization.

161209116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7253 (or 7239 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 161209116 is about 12696.8151912202. The cubic root of 161209116 is about 544.2476120108.

The spelling of 161209116 in words is "one hundred sixty-one million, two hundred nine thousand, one hundred sixteen".