161518501 has 2 divisors, whose sum is σ = 161518502. Its totient is φ = 161518500.

The previous prime is 161518477. The next prime is 161518517. The reversal of 161518501 is 105815161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 107848225 + 53670276 = 10385^2 + 7326^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161518501 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161518501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161518531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80759250 + 80759251.

It is an arithmetic number, because the mean of its divisors is an integer number (80759251).

Almost surely, 2^161518501 is an apocalyptic number.

It is an amenable number.

161518501 is a deficient number, since it is larger than the sum of its proper divisors (1).

161518501 is an equidigital number, since it uses as much as digits as its factorization.

161518501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1200, while the sum is 28.

The square root of 161518501 is about 12708.9929184023. The cubic root of 161518501 is about 544.5955543798.

The spelling of 161518501 in words is "one hundred sixty-one million, five hundred eighteen thousand, five hundred one".