161637 has 16 divisors (see below), whose sum is σ = 253440. Its totient is φ = 89712.

The previous prime is 161627. The next prime is 161639. The reversal of 161637 is 736161.

It is not a de Polignac number, because 161637 - 2⁶ = 161573 is a prime.

It is a super-2 number, since 2×161637² = 52253039538, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 814 + ... + 992.

It is an arithmetic number, because the mean of its divisors is an integer number (15840).

2¹⁶¹⁶³⁷ is an apocalyptic number.

It is an amenable number.

161637 is a deficient number, since it is larger than the sum of its proper divisors (91803).

161637 is a wasteful number, since it uses less digits than its factorization.

161637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232.

The product of its digits is 756, while the sum is 24.

The square root of 161637 is about 402.0410426810. The cubic root of 161637 is about 54.4728703736.

Adding to 161637 its reverse (736161), we get a palindrome (897798).

It can be divided in two parts, 1616 and 37, that added together give a triangular number (1653 = T₅₇).

The spelling of 161637 in words is "one hundred sixty-one thousand, six hundred thirty-seven".