20211120111691 has 2 divisors, whose sum is σ = 20211120111692. Its totient is φ = 20211120111690.

The previous prime is 20211120111673. The next prime is 20211120111703. The reversal of 20211120111691 is 19611102111202.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20211120111691 - 2⁷ = 20211120111563 is a prime.

It is not a weakly prime, because it can be changed into another prime (20211120111631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105560055845 + 10105560055846.

It is an arithmetic number, because the mean of its divisors is an integer number (10105560055846).

Almost surely, 2^{20211120111691} is an apocalyptic number.

20211120111691 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211120111691 is an equidigital number, since it uses as much as digits as its factorization.

20211120111691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 28.

Adding to 20211120111691 its reverse (19611102111202), we get a palindrome (39822222222893).

The spelling of 20211120111691 in words is "twenty trillion, two hundred eleven billion, one hundred twenty million, one hundred eleven thousand, six hundred ninety-one".