161312520 has 32 divisors (see below), whose sum is σ = 483937920. Its totient is φ = 43016640.

The previous prime is 161312513. The next prime is 161312521. The reversal of 161312520 is 25213161.

161312520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (161312521) 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, 672016 + ... + 672255.

It is an arithmetic number, because the mean of its divisors is an integer number (15123060).

Almost surely, 2^161312520 is an apocalyptic number.

161312520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161312520 is an abundant number, since it is smaller than the sum of its proper divisors (322625400).

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

161312520 is a wasteful number, since it uses less digits than its factorization.

161312520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1344285 (or 1344281 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 161312520 is about 12700.8865832272. The cubic root of 161312520 is about 544.3639523129.

Adding to 161312520 its reverse (25213161), we get a palindrome (186525681).

The spelling of 161312520 in words is "one hundred sixty-one million, three hundred twelve thousand, five hundred twenty".