161537 has 4 divisors (see below), whose sum is σ = 164016. Its totient is φ = 159060.

The previous prime is 161531. The next prime is 161543. The reversal of 161537 is 735161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 735161 = 7 ⋅105023.

It is an interprime number because it is at equal distance from previous prime (161531) and next prime (161543).

It is a cyclic number.

It is not a de Polignac number, because 161537 - 2⁴ = 161521 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 161537.

It is not an unprimeable number, because it can be changed into a prime (161531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1139 + ... + 1272.

It is an arithmetic number, because the mean of its divisors is an integer number (41004).

2¹⁶¹⁵³⁷ is an apocalyptic number.

It is an amenable number.

161537 is a deficient number, since it is larger than the sum of its proper divisors (2479).

161537 is an equidigital number, since it uses as much as digits as its factorization.

161537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2478.

The product of its digits is 630, while the sum is 23.

The square root of 161537 is about 401.9166580275. The cubic root of 161537 is about 54.4616344751.

Adding to 161537 its reverse (735161), we get a palindrome (896698).

The spelling of 161537 in words is "one hundred sixty-one thousand, five hundred thirty-seven".