161523919 has 12 divisors (see below), whose sum is σ = 176738112. Its totient is φ = 147103680.

The previous prime is 161523889. The next prime is 161523931. The reversal of 161523919 is 919325161.

It is a happy number.

It is not a de Polignac number, because 161523919 - 2¹³ = 161515727 is a prime.

It is a super-2 number, since 2×161523919² = 52179952818237122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161523419) 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 11 ways as a sum of consecutive naturals, for example, 11394 + ... + 21280.

It is an arithmetic number, because the mean of its divisors is an integer number (14728176).

Almost surely, 2^161523919 is an apocalyptic number.

161523919 is a deficient number, since it is larger than the sum of its proper divisors (15214193).

161523919 is an equidigital number, since it uses as much as digits as its factorization.

161523919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9966 (or 9935 counting only the distinct ones).

The product of its digits is 14580, while the sum is 37.

The square root of 161523919 is about 12709.2060727647. The cubic root of 161523919 is about 544.6016436424.

The spelling of 161523919 in words is "one hundred sixty-one million, five hundred twenty-three thousand, nine hundred nineteen".