22643987 has 4 divisors (see below), whose sum is σ = 22851840. Its totient is φ = 22436136.

The previous prime is 22643969. The next prime is 22644019. The reversal of 22643987 is 78934622.

It is a happy number.

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 22643987 - 2¹² = 22639891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22643087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103763 + ... + 103980.

It is an arithmetic number, because the mean of its divisors is an integer number (5712960).

Almost surely, 2^22643987 is an apocalyptic number.

22643987 is a deficient number, since it is larger than the sum of its proper divisors (207853).

22643987 is a wasteful number, since it uses less digits than its factorization.

22643987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207852.

The product of its digits is 145152, while the sum is 41.

The square root of 22643987 is about 4758.5698481792. The cubic root of 22643987 is about 282.9117373036.

The spelling of 22643987 in words is "twenty-two million, six hundred forty-three thousand, nine hundred eighty-seven".