161520 has 40 divisors (see below), whose sum is σ = 501456. Its totient is φ = 43008.

The previous prime is 161507. The next prime is 161521. The reversal of 161520 is 25161.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 161520.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 161520.

It is not an unprimeable number, because it can be changed into a prime (161521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97 + ... + 576.

2¹⁶¹⁵²⁰ is an apocalyptic number.

161520 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 161520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (250728).

161520 is an abundant number, since it is smaller than the sum of its proper divisors (339936).

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

161520 is a wasteful number, since it uses less digits than its factorization.

161520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689 (or 683 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 161520 is about 401.8955088079. The cubic root of 161520 is about 54.4597239112.

Adding to 161520 its reverse (25161), we get a palindrome (186681).

The spelling of 161520 in words is "one hundred sixty-one thousand, five hundred twenty".