161403728 has 20 divisors (see below), whose sum is σ = 313253760. Its totient is φ = 80564064.

The previous prime is 161403707. The next prime is 161403733. The reversal of 161403728 is 827304161.

161403728 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 161403694 and 161403703.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1403 + ... + 18021.

It is an arithmetic number, because the mean of its divisors is an integer number (15662688).

Almost surely, 2^161403728 is an apocalyptic number.

It is an amenable number.

161403728 is a deficient number, since it is larger than the sum of its proper divisors (151850032).

161403728 is a wasteful number, since it uses less digits than its factorization.

161403728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17234 (or 17228 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 161403728 is about 12704.4766913085. The cubic root of 161403728 is about 544.4665295806.

Adding to 161403728 its reverse (827304161), we get a palindrome (988707889).

The spelling of 161403728 in words is "one hundred sixty-one million, four hundred three thousand, seven hundred twenty-eight".