2201001991 has 2 divisors, whose sum is σ = 2201001992. Its totient is φ = 2201001990.

The previous prime is 2201001989. The next prime is 2201002039. The reversal of 2201001991 is 1991001022.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2201001991 - 2¹ = 2201001989 is a prime.

Together with 2201001989, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2201001911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1100500995 + 1100500996.

It is an arithmetic number, because the mean of its divisors is an integer number (1100500996).

Almost surely, 2^2201001991 is an apocalyptic number.

2201001991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2201001991 is an equidigital number, since it uses as much as digits as its factorization.

2201001991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 2201001991 is about 46914.8376422641. The cubic root of 2201001991 is about 1300.7888685377.

The spelling of 2201001991 in words is "two billion, two hundred one million, one thousand, nine hundred ninety-one".