163631221 has 8 divisors (see below), whose sum is σ = 176548064. Its totient is φ = 150761520.

The previous prime is 163631197. The next prime is 163631231. The reversal of 163631221 is 122136361.

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

It is a de Polignac number, because none of the positive numbers 2^k-163631221 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 (163631231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4395 + ... + 18616.

It is an arithmetic number, because the mean of its divisors is an integer number (22068508).

Almost surely, 2^163631221 is an apocalyptic number.

It is an amenable number.

163631221 is a deficient number, since it is larger than the sum of its proper divisors (12916843).

163631221 is a wasteful number, since it uses less digits than its factorization.

163631221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23571.

The product of its digits is 1296, while the sum is 25.

The square root of 163631221 is about 12791.8419705686. The cubic root of 163631221 is about 546.9597776640.

Adding to 163631221 its reverse (122136361), we get a palindrome (285767582).

The spelling of 163631221 in words is "one hundred sixty-three million, six hundred thirty-one thousand, two hundred twenty-one".