161807819 has 8 divisors (see below), whose sum is σ = 180343440. Its totient is φ = 144274176.

The previous prime is 161807813. The next prime is 161807827. The reversal of 161807819 is 918708161.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161807819 is a prime.

It is a super-2 number, since 2×161807819² = 52363540579073522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161807813) 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, 250154 + ... + 250799.

It is an arithmetic number, because the mean of its divisors is an integer number (22542930).

Almost surely, 2^161807819 is an apocalyptic number.

161807819 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

161807819 is a deficient number, since it is larger than the sum of its proper divisors (18535621).

161807819 is a wasteful number, since it uses less digits than its factorization.

161807819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500989.

The product of its (nonzero) digits is 24192, while the sum is 41.

The square root of 161807819 is about 12720.3702383225. The cubic root of 161807819 is about 544.9205270869.

The spelling of 161807819 in words is "one hundred sixty-one million, eight hundred seven thousand, eight hundred nineteen".