20212021091 has 2 divisors, whose sum is σ = 20212021092. Its totient is φ = 20212021090.

The previous prime is 20212021079. The next prime is 20212021097. The reversal of 20212021091 is 19012021202.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20212021091 - 2¹⁸ = 20211758947 is a prime.

It is not a weakly prime, because it can be changed into another prime (20212021097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10106010545 + 10106010546.

It is an arithmetic number, because the mean of its divisors is an integer number (10106010546).

Almost surely, 2^20212021091 is an apocalyptic number.

20212021091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20212021091 is an equidigital number, since it uses as much as digits as its factorization.

20212021091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 20212021091 its reverse (19012021202), we get a palindrome (39224042293).

The spelling of 20212021091 in words is "twenty billion, two hundred twelve million, twenty-one thousand, ninety-one".