22221978 has 32 divisors (see below), whose sum is σ = 47132160. Its totient is φ = 6972480.

The previous prime is 22221977. The next prime is 22222049. The reversal of 22221978 is 87912222.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (22221971) 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 15 ways as a sum of consecutive naturals, for example, 5268 + ... + 8496.

It is an arithmetic number, because the mean of its divisors is an integer number (1472880).

Almost surely, 2^22221978 is an apocalyptic number.

22221978 is an abundant number, since it is smaller than the sum of its proper divisors (24910182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

22221978 is a wasteful number, since it uses less digits than its factorization.

22221978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3302.

The product of its digits is 8064, while the sum is 33.

The square root of 22221978 is about 4714.0193041607. The cubic root of 22221978 is about 281.1431918385.

The spelling of 22221978 in words is "twenty-two million, two hundred twenty-one thousand, nine hundred seventy-eight".