20782213 has 2 divisors, whose sum is σ = 20782214. Its totient is φ = 20782212.

The previous prime is 20782193. The next prime is 20782217. The reversal of 20782213 is 31228702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20088324 + 693889 = 4482^2 + 833^2 .

It is a cyclic number.

It is not a de Polignac number, because 20782213 - 2¹³ = 20774021 is a prime.

It is equal to p_1317067 and since 20782213 and 1317067 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20782217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10391106 + 10391107.

It is an arithmetic number, because the mean of its divisors is an integer number (10391107).

Almost surely, 2^20782213 is an apocalyptic number.

It is an amenable number.

20782213 is a deficient number, since it is larger than the sum of its proper divisors (1).

20782213 is an equidigital number, since it uses as much as digits as its factorization.

20782213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 20782213 is about 4558.7512544555. The cubic root of 20782213 is about 274.9353589114.

The spelling of 20782213 in words is "twenty million, seven hundred eighty-two thousand, two hundred thirteen".