20012121091 has 2 divisors, whose sum is σ = 20012121092. Its totient is φ = 20012121090.

The previous prime is 20012121079. The next prime is 20012121097. The reversal of 20012121091 is 19012121002.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20012121091 - 2⁷ = 20012120963 is a prime.

It is a super-3 number, since 3×20012121091³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (20012121097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10006060545 + 10006060546.

It is an arithmetic number, because the mean of its divisors is an integer number (10006060546).

Almost surely, 2^20012121091 is an apocalyptic number.

20012121091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20012121091 is an equidigital number, since it uses as much as digits as its factorization.

20012121091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 20012121091 its reverse (19012121002), we get a palindrome (39024242093).

The spelling of 20012121091 in words is "twenty billion, twelve million, one hundred twenty-one thousand, ninety-one".