20201121121091 has 2 divisors, whose sum is σ = 20201121121092. Its totient is φ = 20201121121090.

The previous prime is 20201121121073. The next prime is 20201121121183. The reversal of 20201121121091 is 19012112110202.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20201121121091 - 2¹⁴ = 20201121104707 is a prime.

It is not a weakly prime, because it can be changed into another prime (20201121123091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10100560560545 + 10100560560546.

It is an arithmetic number, because the mean of its divisors is an integer number (10100560560546).

Almost surely, 2^{20201121121091} is an apocalyptic number.

20201121121091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20201121121091 is an equidigital number, since it uses as much as digits as its factorization.

20201121121091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 23.

Adding to 20201121121091 its reverse (19012112110202), we get a palindrome (39213233231293).

The spelling of 20201121121091 in words is "twenty trillion, two hundred one billion, one hundred twenty-one million, one hundred twenty-one thousand, ninety-one".