22111891661 has 2 divisors, whose sum is σ = 22111891662. Its totient is φ = 22111891660.

The previous prime is 22111891657. The next prime is 22111891663. The reversal of 22111891661 is 16619811122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11953267561 + 10158624100 = 109331^2 + 100790^2 .

It is a cyclic number.

It is not a de Polignac number, because 22111891661 - 2² = 22111891657 is a prime.

Together with 22111891663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22111891663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11055945830 + 11055945831.

It is an arithmetic number, because the mean of its divisors is an integer number (11055945831).

Almost surely, 2^22111891661 is an apocalyptic number.

It is an amenable number.

22111891661 is a deficient number, since it is larger than the sum of its proper divisors (1).

22111891661 is an equidigital number, since it uses as much as digits as its factorization.

22111891661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 38.

The spelling of 22111891661 in words is "twenty-two billion, one hundred eleven million, eight hundred ninety-one thousand, six hundred sixty-one".