22198991 has 4 divisors (see below), whose sum is σ = 23504832. Its totient is φ = 20893152.

The previous prime is 22198987. The next prime is 22199029. The reversal of 22198991 is 19989122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 22198991 - 2² = 22198987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22198951) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 652895 + ... + 652928.

It is an arithmetic number, because the mean of its divisors is an integer number (5876208).

Almost surely, 2^22198991 is an apocalyptic number.

22198991 is a deficient number, since it is larger than the sum of its proper divisors (1305841).

22198991 is a wasteful number, since it uses less digits than its factorization.

22198991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1305840.

The product of its digits is 23328, while the sum is 41.

The square root of 22198991 is about 4711.5805203774. The cubic root of 22198991 is about 281.0462177496.

The spelling of 22198991 in words is "twenty-two million, one hundred ninety-eight thousand, nine hundred ninety-one".