22801991 has 4 divisors (see below), whose sum is σ = 22976184. Its totient is φ = 22627800.

The previous prime is 22801979. The next prime is 22802011. The reversal of 22801991 is 19910822.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22801991 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 (22801291) 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, 86900 + ... + 87161.

It is an arithmetic number, because the mean of its divisors is an integer number (5744046).

Almost surely, 2^22801991 is an apocalyptic number.

22801991 is a deficient number, since it is larger than the sum of its proper divisors (174193).

22801991 is a wasteful number, since it uses less digits than its factorization.

22801991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174192.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 22801991 is about 4775.1430345069. The cubic root of 22801991 is about 283.5682414805.

The spelling of 22801991 in words is "twenty-two million, eight hundred one thousand, nine hundred ninety-one".