161231535 has 12 divisors (see below), whose sum is σ = 279468072. Its totient is φ = 85990128.

The previous prime is 161231531. The next prime is 161231569. The reversal of 161231535 is 535132161.

161231535 is a `hidden beast` number, since 1 + 6 + 123 + 1 + 535 = 666.

It is not a de Polignac number, because 161231535 - 2² = 161231531 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 161231499 and 161231508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161231531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1791417 + ... + 1791506.

It is an arithmetic number, because the mean of its divisors is an integer number (23289006).

Almost surely, 2^161231535 is an apocalyptic number.

161231535 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

161231535 is a deficient number, since it is larger than the sum of its proper divisors (118236537).

161231535 is a wasteful number, since it uses less digits than its factorization.

161231535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3582934 (or 3582931 counting only the distinct ones).

The product of its digits is 2700, while the sum is 27.

The square root of 161231535 is about 12697.6980197200. The cubic root of 161231535 is about 544.2728399507.

Adding to 161231535 its reverse (535132161), we get a palindrome (696363696).

The spelling of 161231535 in words is "one hundred sixty-one million, two hundred thirty-one thousand, five hundred thirty-five".