20221215 has 16 divisors (see below), whose sum is σ = 36976128. Its totient is φ = 9243936.

The previous prime is 20221213. The next prime is 20221231. The reversal of 20221215 is 51212202.

It is not a de Polignac number, because 20221215 - 2¹ = 20221213 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a junction number, because it is equal to n+sod(n) for n = 20221194 and 20221203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20221213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 96187 + ... + 96396.

It is an arithmetic number, because the mean of its divisors is an integer number (2311008).

Almost surely, 2^20221215 is an apocalyptic number.

20221215 is a deficient number, since it is larger than the sum of its proper divisors (16754913).

20221215 is a wasteful number, since it uses less digits than its factorization.

20221215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192598.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 20221215 is about 4496.8005292652. The cubic root of 20221215 is about 272.4388775180.

Adding to 20221215 its reverse (51212202), we get a palindrome (71433417).

The spelling of 20221215 in words is "twenty million, two hundred twenty-one thousand, two hundred fifteen".