20930221 has 4 divisors (see below), whose sum is σ = 22540252. Its totient is φ = 19320192.

The previous prime is 20930209. The next prime is 20930227. The reversal of 20930221 is 12203902.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12744900 + 8185321 = 3570^2 + 2861^2 .

It is a cyclic number.

It is not a de Polignac number, because 20930221 - 2⁷ = 20930093 is a prime.

It is a super-2 number, since 2×20930221² = 876148302217682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20930227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 804996 + ... + 805021.

It is an arithmetic number, because the mean of its divisors is an integer number (5635063).

Almost surely, 2^20930221 is an apocalyptic number.

It is an amenable number.

20930221 is a deficient number, since it is larger than the sum of its proper divisors (1610031).

20930221 is a wasteful number, since it uses less digits than its factorization.

20930221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1610030.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 20930221 is about 4574.9558467815. The cubic root of 20930221 is about 275.5864992337.

The spelling of 20930221 in words is "twenty million, nine hundred thirty thousand, two hundred twenty-one".