161540537 has 2 divisors, whose sum is σ = 161540538. Its totient is φ = 161540536.

The previous prime is 161540513. The next prime is 161540539. The reversal of 161540537 is 735045161.

161540537 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 107723641 + 53816896 = 10379^2 + 7336^2 .

It is a cyclic number.

It is not a de Polignac number, because 161540537 - 2²⁴ = 144763321 is a prime.

Together with 161540539, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161540539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80770268 + 80770269.

It is an arithmetic number, because the mean of its divisors is an integer number (80770269).

Almost surely, 2^161540537 is an apocalyptic number.

It is an amenable number.

161540537 is a deficient number, since it is larger than the sum of its proper divisors (1).

161540537 is an equidigital number, since it uses as much as digits as its factorization.

161540537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 161540537 is about 12709.8598340029. The cubic root of 161540537 is about 544.6203196788.

Adding to 161540537 its reverse (735045161), we get a palindrome (896585698).

The spelling of 161540537 in words is "one hundred sixty-one million, five hundred forty thousand, five hundred thirty-seven".