20087021 has 2 divisors, whose sum is σ = 20087022. Its totient is φ = 20087020.

The previous prime is 20086991. The next prime is 20087059. The reversal of 20087021 is 12078002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12524521 + 7562500 = 3539^2 + 2750^2 .

It is a cyclic number.

It is not a de Polignac number, because 20087021 - 2¹⁸ = 19824877 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20086984 and 20087002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20087521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10043510 + 10043511.

It is an arithmetic number, because the mean of its divisors is an integer number (10043511).

Almost surely, 2^20087021 is an apocalyptic number.

It is an amenable number.

20087021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20087021 is an equidigital number, since it uses as much as digits as its factorization.

20087021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 20087021 is about 4481.8546384282. The cubic root of 20087021 is about 271.8348776129.

The spelling of 20087021 in words is "twenty million, eighty-seven thousand, twenty-one".