161691103 has 8 divisors (see below), whose sum is σ = 184988672. Its totient is φ = 138443256.

The previous prime is 161691059. The next prime is 161691107. The reversal of 161691103 is 301196161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161691103 - 2¹⁷ = 161560031 is a prime.

It is a super-2 number, since 2×161691103² = 52288025578713218, 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 (161691107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5175 + ... + 18712.

It is an arithmetic number, because the mean of its divisors is an integer number (23123584).

Almost surely, 2^161691103 is an apocalyptic number.

161691103 is a deficient number, since it is larger than the sum of its proper divisors (23297569).

161691103 is an equidigital number, since it uses as much as digits as its factorization.

161691103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24861.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 161691103 is about 12715.7816511609. The cubic root of 161691103 is about 544.7894739996.

The spelling of 161691103 in words is "one hundred sixty-one million, six hundred ninety-one thousand, one hundred three".