18221626 has 4 divisors (see below), whose sum is σ = 27332442. Its totient is φ = 9110812.

The previous prime is 18221611. The next prime is 18221629. The reversal of 18221626 is 62612281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 62612281 = 31 ⋅2019751.

It can be written as a sum of positive squares in only one way, i.e., 18020025 + 201601 = 4245^2 + 449^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18221594 and 18221603.

It is not an unprimeable number, because it can be changed into a prime (18221629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4555405 + ... + 4555408.

Almost surely, 2^18221626 is an apocalyptic number.

18221626 is a deficient number, since it is larger than the sum of its proper divisors (9110816).

18221626 is an equidigital number, since it uses as much as digits as its factorization.

18221626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9110815.

The product of its digits is 2304, while the sum is 28.

The square root of 18221626 is about 4268.6796553501. The cubic root of 18221626 is about 263.1453557071.

The spelling of 18221626 in words is "eighteen million, two hundred twenty-one thousand, six hundred twenty-six".