2191997699 has 2 divisors, whose sum is σ = 2191997700. Its totient is φ = 2191997698.

The previous prime is 2191997657. The next prime is 2191997701. The reversal of 2191997699 is 9967991912.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2191997699 - 2⁸ = 2191997443 is a prime.

Together with 2191997701, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2191997299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1095998849 + 1095998850.

It is an arithmetic number, because the mean of its divisors is an integer number (1095998850).

Almost surely, 2^2191997699 is an apocalyptic number.

2191997699 is a deficient number, since it is larger than the sum of its proper divisors (1).

2191997699 is an equidigital number, since it uses as much as digits as its factorization.

2191997699 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4960116, while the sum is 62.

The square root of 2191997699 is about 46818.7750694099. The cubic root of 2191997699 is about 1299.0126030862.

The spelling of 2191997699 in words is "two billion, one hundred ninety-one million, nine hundred ninety-seven thousand, six hundred ninety-nine".