22008991 has 8 divisors (see below), whose sum is σ = 22588544. Its totient is φ = 21432600.

The previous prime is 22008979. The next prime is 22009003. The reversal of 22008991 is 19980022.

It is an interprime number because it is at equal distance from previous prime (22008979) and next prime (22009003).

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-22008991 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 (22008901) 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, 20416 + ... + 21466.

It is an arithmetic number, because the mean of its divisors is an integer number (2823568).

Almost surely, 2^22008991 is an apocalyptic number.

22008991 is a deficient number, since it is larger than the sum of its proper divisors (579553).

22008991 is a wasteful number, since it uses less digits than its factorization.

22008991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1581.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 22008991 is about 4691.3741057392. The cubic root of 22008991 is about 280.2420992843.

The spelling of 22008991 in words is "twenty-two million, eight thousand, nine hundred ninety-one".