161136720 has 120 divisors (see below), whose sum is σ = 569680800. Its totient is φ = 40704768.

The previous prime is 161136719. The next prime is 161136721. The reversal of 161136720 is 27631161.

It is an interprime number because it is at equal distance from previous prime (161136719) and next prime (161136721).

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161136721) 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, 7791 + ... + 19569.

It is an arithmetic number, because the mean of its divisors is an integer number (4747340).

Almost surely, 2^161136720 is an apocalyptic number.

161136720 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 161136720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (284840400).

161136720 is an abundant number, since it is smaller than the sum of its proper divisors (408544080).

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

161136720 is a wasteful number, since it uses less digits than its factorization.

161136720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11817 (or 11808 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 161136720 is about 12693.9639199109. The cubic root of 161136720 is about 544.1661293364.

Adding to 161136720 its reverse (27631161), we get a palindrome (188767881).

The spelling of 161136720 in words is "one hundred sixty-one million, one hundred thirty-six thousand, seven hundred twenty".