20021369 has 2 divisors, whose sum is σ = 20021370. Its totient is φ = 20021368.

The previous prime is 20021363. The next prime is 20021387. The reversal of 20021369 is 96312002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18593344 + 1428025 = 4312^2 + 1195^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20021369 is a prime.

It is a super-2 number, since 2×20021369² = 801710433268322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20021363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010684 + 10010685.

It is an arithmetic number, because the mean of its divisors is an integer number (10010685).

Almost surely, 2^20021369 is an apocalyptic number.

It is an amenable number.

20021369 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021369 is an equidigital number, since it uses as much as digits as its factorization.

20021369 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 20021369 is about 4474.5244440052. The cubic root of 20021369 is about 271.5384012329.

The spelling of 20021369 in words is "twenty million, twenty-one thousand, three hundred sixty-nine".