20965221 has 6 divisors (see below), whose sum is σ = 30283110. Its totient is φ = 13976808.

The previous prime is 20965193. The next prime is 20965249. The reversal of 20965221 is 12256902.

20965221 is a `hidden beast` number, since 2 + 0 + 9 + 652 + 2 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (20965193) and next prime (20965249).

It can be written as a sum of positive squares in only one way, i.e., 20930625 + 34596 = 4575^2 + 186^2 .

It is not a de Polignac number, because 20965221 - 2¹⁰ = 20964197 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20965271) 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 5 ways as a sum of consecutive naturals, for example, 1164726 + ... + 1164743.

It is an arithmetic number, because the mean of its divisors is an integer number (5047185).

Almost surely, 2^20965221 is an apocalyptic number.

It is an amenable number.

20965221 is a deficient number, since it is larger than the sum of its proper divisors (9317889).

20965221 is a wasteful number, since it uses less digits than its factorization.

20965221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2329475 (or 2329472 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 20965221 is about 4578.7794225099. The cubic root of 20965221 is about 275.7400277284.

The spelling of 20965221 in words is "twenty million, nine hundred sixty-five thousand, two hundred twenty-one".