21922018 has 4 divisors (see below), whose sum is σ = 32883030. Its totient is φ = 10961008.

The previous prime is 21922009. The next prime is 21922037. The reversal of 21922018 is 81022912.

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., 14265729 + 7656289 = 3777^2 + 2767^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21921983 and 21922001.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5480503 + ... + 5480506.

Almost surely, 2^21922018 is an apocalyptic number.

21922018 is a deficient number, since it is larger than the sum of its proper divisors (10961012).

21922018 is a wasteful number, since it uses less digits than its factorization.

21922018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10961011.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 21922018 is about 4682.0954710471. The cubic root of 21922018 is about 279.8724674313.

The spelling of 21922018 in words is "twenty-one million, nine hundred twenty-two thousand, eighteen".