221630121 has 16 divisors (see below), whose sum is σ = 332968320. Its totient is φ = 145671120.

The previous prime is 221630089. The next prime is 221630219. The reversal of 221630121 is 121036122.

221630121 is a `hidden beast` number, since 2 + 21 + 630 + 12 + 1 = 666.

It is not a de Polignac number, because 221630121 - 2⁵ = 221630089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221630094 and 221630103.

It is not an unprimeable number, because it can be changed into a prime (221630021) 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, 55890 + ... + 59723.

It is an arithmetic number, because the mean of its divisors is an integer number (20810520).

Almost surely, 2^221630121 is an apocalyptic number.

It is an amenable number.

221630121 is a deficient number, since it is larger than the sum of its proper divisors (111338199).

221630121 is a wasteful number, since it uses less digits than its factorization.

221630121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115693 (or 115687 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 221630121 is about 14887.2469248011. The cubic root of 221630121 is about 605.1684261170.

Adding to 221630121 its reverse (121036122), we get a palindrome (342666243).

The spelling of 221630121 in words is "two hundred twenty-one million, six hundred thirty thousand, one hundred twenty-one".