161823397 has 4 divisors (see below), whose sum is σ = 165266496. Its totient is φ = 158380300.

The previous prime is 161823353. The next prime is 161823401. The reversal of 161823397 is 793328161.

161823397 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, and also an emirpimes, since its reverse is a distinct semiprime: 793328161 = 31 ⋅25591231.

It is a cyclic number.

It is not a de Polignac number, because 161823397 - 2¹⁹ = 161299109 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 (161826397) 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, 1721479 + ... + 1721572.

It is an arithmetic number, because the mean of its divisors is an integer number (41316624).

Almost surely, 2^161823397 is an apocalyptic number.

It is an amenable number.

161823397 is a deficient number, since it is larger than the sum of its proper divisors (3443099).

161823397 is an equidigital number, since it uses as much as digits as its factorization.

161823397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3443098.

The product of its digits is 54432, while the sum is 40.

The square root of 161823397 is about 12720.9825485298. The cubic root of 161823397 is about 544.9380138800.

The spelling of 161823397 in words is "one hundred sixty-one million, eight hundred twenty-three thousand, three hundred ninety-seven".