161538617 has 4 divisors (see below), whose sum is σ = 161612880. Its totient is φ = 161464356.

The previous prime is 161538557. The next prime is 161538623. The reversal of 161538617 is 716835161.

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.

It is a cyclic number.

It is not a de Polignac number, because 161538617 - 2²⁰ = 160490041 is a prime.

It is a super-3 number, since 3×161538617³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161538677) 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, 33767 + ... + 38252.

It is an arithmetic number, because the mean of its divisors is an integer number (40403220).

Almost surely, 2^161538617 is an apocalyptic number.

It is an amenable number.

161538617 is a deficient number, since it is larger than the sum of its proper divisors (74263).

161538617 is an equidigital number, since it uses as much as digits as its factorization.

161538617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74262.

The product of its digits is 30240, while the sum is 38.

The square root of 161538617 is about 12709.7843018676. The cubic root of 161538617 is about 544.6181619642.

The spelling of 161538617 in words is "one hundred sixty-one million, five hundred thirty-eight thousand, six hundred seventeen".