161803813 has 4 divisors (see below), whose sum is σ = 162254880. Its totient is φ = 161352748.

The previous prime is 161803799. The next prime is 161803819. The reversal of 161803813 is 318308161.

161803813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161803813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161803819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 224995 + ... + 225712.

It is an arithmetic number, because the mean of its divisors is an integer number (40563720).

Almost surely, 2^161803813 is an apocalyptic number.

It is an amenable number.

161803813 is a deficient number, since it is larger than the sum of its proper divisors (451067).

161803813 is an equidigital number, since it uses as much as digits as its factorization.

161803813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451066.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 161803813 is about 12720.2127733777. The cubic root of 161803813 is about 544.9160300449.

The spelling of 161803813 in words is "one hundred sixty-one million, eight hundred three thousand, eight hundred thirteen".