20310221 has 12 divisors (see below), whose sum is σ = 21652992. Its totient is φ = 19046664.

The previous prime is 20310217. The next prime is 20310247. The reversal of 20310221 is 12201302.

It is a happy number.

It is not a de Polignac number, because 20310221 - 2² = 20310217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20310271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 45626 + ... + 46068.

It is an arithmetic number, because the mean of its divisors is an integer number (1804416).

Almost surely, 2^20310221 is an apocalyptic number.

It is an amenable number.

20310221 is a deficient number, since it is larger than the sum of its proper divisors (1342771).

20310221 is a wasteful number, since it uses less digits than its factorization.

20310221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 608 (or 589 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 20310221 is about 4506.6862548884. The cubic root of 20310221 is about 272.8380161400.

Adding to 20310221 its reverse (12201302), we get a palindrome (32511523).

The spelling of 20310221 in words is "twenty million, three hundred ten thousand, two hundred twenty-one".