22231978 has 4 divisors (see below), whose sum is σ = 33347970. Its totient is φ = 11115988.

The previous prime is 22231973. The next prime is 22231981. The reversal of 22231978 is 87913222.

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

It can be written as a sum of positive squares in only one way, i.e., 17665209 + 4566769 = 4203^2 + 2137^2 .

It is not an unprimeable number, because it can be changed into a prime (22231973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5557993 + ... + 5557996.

Almost surely, 2^22231978 is an apocalyptic number.

22231978 is a deficient number, since it is larger than the sum of its proper divisors (11115992).

22231978 is a wasteful number, since it uses less digits than its factorization.

22231978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11115991.

The product of its digits is 12096, while the sum is 34.

The square root of 22231978 is about 4715.0798508615. The cubic root of 22231978 is about 281.1853574564.

The spelling of 22231978 in words is "twenty-two million, two hundred thirty-one thousand, nine hundred seventy-eight".