161511612 has 96 divisors (see below), whose sum is σ = 416317440. Its totient is φ = 48565440.

The previous prime is 161511547. The next prime is 161511613. The reversal of 161511612 is 216115161.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161511613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 367689 + ... + 368127.

It is an arithmetic number, because the mean of its divisors is an integer number (4336640).

Almost surely, 2^161511612 is an apocalyptic number.

161511612 is a gapful number since it is divisible by the number (12) 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 161511612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (208158720).

161511612 is an abundant number, since it is smaller than the sum of its proper divisors (254805828).

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

161511612 is a wasteful number, since it uses less digits than its factorization.

161511612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543 (or 541 counting only the distinct ones).

The product of its digits is 360, while the sum is 24.

The square root of 161511612 is about 12708.7218869562. The cubic root of 161511612 is about 544.5878116711.

Adding to 161511612 its reverse (216115161), we get a palindrome (377626773).

The spelling of 161511612 in words is "one hundred sixty-one million, five hundred eleven thousand, six hundred twelve".