20021311 has 2 divisors, whose sum is σ = 20021312. Its totient is φ = 20021310.

The previous prime is 20021303. The next prime is 20021321. The reversal of 20021311 is 11312002.

It is an a-pointer prime, because the next prime (20021321) can be obtained adding 20021311 to its sum of digits (10).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20021311 - 2³ = 20021303 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021321) 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, 10010655 + 10010656.

It is an arithmetic number, because the mean of its divisors is an integer number (10010656).

Almost surely, 2^20021311 is an apocalyptic number.

20021311 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021311 is an equidigital number, since it uses as much as digits as its factorization.

20021311 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 20021311 is about 4474.5179628648. The cubic root of 20021311 is about 271.5381390257.

Adding to 20021311 its reverse (11312002), we get a palindrome (31333313).

The spelling of 20021311 in words is "twenty million, twenty-one thousand, three hundred eleven".