161531536 has 10 divisors (see below), whose sum is σ = 312967382. Its totient is φ = 80765760.

The previous prime is 161531497. The next prime is 161531551. The reversal of 161531536 is 635135161.

It can be written as a sum of positive squares in only one way, i.e., 96825600 + 64705936 = 9840^2 + 8044^2 .

It is a junction number, because it is equal to n+sod(n) for n = 161531498 and 161531507.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5047845 + ... + 5047876.

Almost surely, 2^161531536 is an apocalyptic number.

161531536 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

161531536 is a deficient number, since it is larger than the sum of its proper divisors (151435846).

161531536 is a wasteful number, since it uses less digits than its factorization.

161531536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10095729 (or 10095723 counting only the distinct ones).

The product of its digits is 8100, while the sum is 31.

The square root of 161531536 is about 12709.5057338985. The cubic root of 161531536 is about 544.6102041197.

Adding to 161531536 its reverse (635135161), we get a palindrome (796666697).

It can be divided in two parts, 16153 and 1536, that added together give a square (17689 = 133²).

The spelling of 161531536 in words is "one hundred sixty-one million, five hundred thirty-one thousand, five hundred thirty-six".