20875221 has 6 divisors (see below), whose sum is σ = 30153110. Its totient is φ = 13916808.

The previous prime is 20875219. The next prime is 20875223. The reversal of 20875221 is 12257802.

It is an interprime number because it is at equal distance from previous prime (20875219) and next prime (20875223).

It can be written as a sum of positive squares in only one way, i.e., 19847025 + 1028196 = 4455^2 + 1014^2 .

It is not a de Polignac number, because 20875221 - 2¹ = 20875219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20875223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1159726 + ... + 1159743.

Almost surely, 2^20875221 is an apocalyptic number.

It is an amenable number.

20875221 is a deficient number, since it is larger than the sum of its proper divisors (9277889).

20875221 is a wasteful number, since it uses less digits than its factorization.

20875221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2319475 (or 2319472 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 20875221 is about 4568.9409057242. The cubic root of 20875221 is about 275.3448939887.

The spelling of 20875221 in words is "twenty million, eight hundred seventy-five thousand, two hundred twenty-one".