20021205091 has 2 divisors, whose sum is σ = 20021205092. Its totient is φ = 20021205090.

The previous prime is 20021205041. The next prime is 20021205101. The reversal of 20021205091 is 19050212002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20021205091 - 2¹⁷ = 20021074019 is a prime.

It is not a weakly prime, because it can be changed into another prime (20021205041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010602545 + 10010602546.

It is an arithmetic number, because the mean of its divisors is an integer number (10010602546).

Almost surely, 2^20021205091 is an apocalyptic number.

20021205091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021205091 is an equidigital number, since it uses as much as digits as its factorization.

20021205091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 22.

Adding to 20021205091 its reverse (19050212002), we get a palindrome (39071417093).

The spelling of 20021205091 in words is "twenty billion, twenty-one million, two hundred five thousand, ninety-one".