20827021 has 4 divisors (see below), whose sum is σ = 21923200. Its totient is φ = 19730844.

The previous prime is 20827013. The next prime is 20827043. The reversal of 20827021 is 12072802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20827021 - 2³ = 20827013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20826983 and 20827001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20827061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 548061 + ... + 548098.

It is an arithmetic number, because the mean of its divisors is an integer number (5480800).

Almost surely, 2^20827021 is an apocalyptic number.

It is an amenable number.

20827021 is a deficient number, since it is larger than the sum of its proper divisors (1096179).

20827021 is a wasteful number, since it uses less digits than its factorization.

20827021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1096178.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 20827021 is about 4563.6631120187. The cubic root of 20827021 is about 275.1328107801.

Adding to 20827021 its reverse (12072802), we get a palindrome (32899823).

The spelling of 20827021 in words is "twenty million, eight hundred twenty-seven thousand, twenty-one".