20402211091 has 2 divisors, whose sum is σ = 20402211092. Its totient is φ = 20402211090.

The previous prime is 20402211047. The next prime is 20402211121. The reversal of 20402211091 is 19011220402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20402211091 - 2¹⁵ = 20402178323 is a prime.

It is not a weakly prime, because it can be changed into another prime (20402241091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10201105545 + 10201105546.

It is an arithmetic number, because the mean of its divisors is an integer number (10201105546).

Almost surely, 2^20402211091 is an apocalyptic number.

20402211091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20402211091 is an equidigital number, since it uses as much as digits as its factorization.

20402211091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 20402211091 its reverse (19011220402), we get a palindrome (39413431493).

The spelling of 20402211091 in words is "twenty billion, four hundred two million, two hundred eleven thousand, ninety-one".