161801516 has 18 divisors (see below), whose sum is σ = 287473788. Its totient is φ = 79684440.

The previous prime is 161801513. The next prime is 161801533. The reversal of 161801516 is 615108161.

161801516 is digitally balanced in base 3 and base 9, because in such bases it contains all the possibile digits an equal number of times.

161801516 is strictly pandigital in base 9.

It is not an unprimeable number, because it can be changed into a prime (161801513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13451 + ... + 22461.

It is an arithmetic number, because the mean of its divisors is an integer number (15970766).

Almost surely, 2^161801516 is an apocalyptic number.

It is an amenable number.

161801516 is a deficient number, since it is larger than the sum of its proper divisors (125672272).

161801516 is an equidigital number, since it uses as much as digits as its factorization.

161801516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9149 (or 9080 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 29.

The square root of 161801516 is about 12720.1224836870. The cubic root of 161801516 is about 544.9134514529.

Adding to 161801516 its reverse (615108161), we get a palindrome (776909677).

The spelling of 161801516 in words is "one hundred sixty-one million, eight hundred one thousand, five hundred sixteen".