20315221 has 8 divisors (see below), whose sum is σ = 22011264. Its totient is φ = 18674880.

The previous prime is 20315219. The next prime is 20315227. The reversal of 20315221 is 12251302.

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

It is a cyclic number.

It is not a de Polignac number, because 20315221 - 2¹ = 20315219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20315195 and 20315204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20315227) 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, 13165 + ... + 14626.

It is an arithmetic number, because the mean of its divisors is an integer number (2751408).

Almost surely, 2^20315221 is an apocalyptic number.

It is an amenable number.

20315221 is a deficient number, since it is larger than the sum of its proper divisors (1696043).

20315221 is a wasteful number, since it uses less digits than its factorization.

20315221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27851.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 20315221 is about 4507.2409520681. The cubic root of 20315221 is about 272.8604035240.

Adding to 20315221 its reverse (12251302), we get a palindrome (32566523).

The spelling of 20315221 in words is "twenty million, three hundred fifteen thousand, two hundred twenty-one".