22201991 has 8 divisors (see below), whose sum is σ = 25752960. Its totient is φ = 18745848.

The previous prime is 22201967. The next prime is 22201999. The reversal of 22201991 is 19910222.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22201991 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 22201991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22201999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23201 + ... + 24138.

It is an arithmetic number, because the mean of its divisors is an integer number (3219120).

Almost surely, 2^22201991 is an apocalyptic number.

22201991 is a deficient number, since it is larger than the sum of its proper divisors (3550969).

22201991 is an equidigital number, since it uses as much as digits as its factorization.

22201991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47413.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 22201991 is about 4711.8988741271. The cubic root of 22201991 is about 281.0588774943.

The spelling of 22201991 in words is "twenty-two million, two hundred one thousand, nine hundred ninety-one".