161516489 has 4 divisors (see below), whose sum is σ = 162353556. Its totient is φ = 160679424.

The previous prime is 161516483. The next prime is 161516497. The reversal of 161516489 is 984615161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 984615161 = 43 ⋅22898027.

It can be written as a sum of positive squares in 2 ways, for example, as 86174089 + 75342400 = 9283^2 + 8680^2 .

It is a cyclic number.

It is not a de Polignac number, because 161516489 - 2⁸ = 161516233 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161516483) 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, 418244 + ... + 418629.

It is an arithmetic number, because the mean of its divisors is an integer number (40588389).

Almost surely, 2^161516489 is an apocalyptic number.

It is an amenable number.

161516489 is a deficient number, since it is larger than the sum of its proper divisors (837067).

161516489 is an equidigital number, since it uses as much as digits as its factorization.

161516489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 837066.

The product of its digits is 51840, while the sum is 41.

The square root of 161516489 is about 12708.9137616084. The cubic root of 161516489 is about 544.5932930686.

The spelling of 161516489 in words is "one hundred sixty-one million, five hundred sixteen thousand, four hundred eighty-nine".