163442721 has 16 divisors (see below), whose sum is σ = 235751936. Its totient is φ = 100123776.

The previous prime is 163442717. The next prime is 163442723. The reversal of 163442721 is 127244361.

163442721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 163442721 - 2² = 163442717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163442723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 700 + ... + 18093.

It is an arithmetic number, because the mean of its divisors is an integer number (14734496).

Almost surely, 2^163442721 is an apocalyptic number.

It is an amenable number.

163442721 is a deficient number, since it is larger than the sum of its proper divisors (72309215).

163442721 is a wasteful number, since it uses less digits than its factorization.

163442721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19032.

The product of its digits is 8064, while the sum is 30.

The square root of 163442721 is about 12784.4718702025. The cubic root of 163442721 is about 546.7496679362.

The spelling of 163442721 in words is "one hundred sixty-three million, four hundred forty-two thousand, seven hundred twenty-one".