22191391 has 2 divisors, whose sum is σ = 22191392. Its totient is φ = 22191390.

The previous prime is 22191361. The next prime is 22191401. The reversal of 22191391 is 19319122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 22191391 - 2¹⁵ = 22158623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22191361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11095695 + 11095696.

It is an arithmetic number, because the mean of its divisors is an integer number (11095696).

Almost surely, 2^22191391 is an apocalyptic number.

22191391 is a deficient number, since it is larger than the sum of its proper divisors (1).

22191391 is an equidigital number, since it uses as much as digits as its factorization.

22191391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 28.

The square root of 22191391 is about 4710.7739279231. The cubic root of 22191391 is about 281.0141412909.

The spelling of 22191391 in words is "twenty-two million, one hundred ninety-one thousand, three hundred ninety-one".