20832821 has 2 divisors, whose sum is σ = 20832822. Its totient is φ = 20832820.

The previous prime is 20832767. The next prime is 20832859. The reversal of 20832821 is 12823802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20702500 + 130321 = 4550^2 + 361^2 .

It is a cyclic number.

It is not a de Polignac number, because 20832821 - 2¹⁴ = 20816437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20832881) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10416410 + 10416411.

It is an arithmetic number, because the mean of its divisors is an integer number (10416411).

Almost surely, 2^20832821 is an apocalyptic number.

It is an amenable number.

20832821 is a deficient number, since it is larger than the sum of its proper divisors (1).

20832821 is an equidigital number, since it uses as much as digits as its factorization.

20832821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 20832821 is about 4564.2985222266. The cubic root of 20832821 is about 275.1583484729.

The spelling of 20832821 in words is "twenty million, eight hundred thirty-two thousand, eight hundred twenty-one".