22128987 has 4 divisors (see below), whose sum is σ = 29505320. Its totient is φ = 14752656.

The previous prime is 22128973. The next prime is 22128989. The reversal of 22128987 is 78982122.

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

It is not a de Polignac number, because 22128987 - 2⁷ = 22128859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22128989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3688162 + ... + 3688167.

It is an arithmetic number, because the mean of its divisors is an integer number (7376330).

Almost surely, 2^22128987 is an apocalyptic number.

22128987 is a deficient number, since it is larger than the sum of its proper divisors (7376333).

22128987 is an equidigital number, since it uses as much as digits as its factorization.

22128987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7376332.

The product of its digits is 32256, while the sum is 39.

The square root of 22128987 is about 4704.1457247836. The cubic root of 22128987 is about 280.7504824373.

The spelling of 22128987 in words is "twenty-two million, one hundred twenty-eight thousand, nine hundred eighty-seven".