18220633 has 2 divisors, whose sum is σ = 18220634. Its totient is φ = 18220632.

The previous prime is 18220621. The next prime is 18220637. The reversal of 18220633 is 33602281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12475024 + 5745609 = 3532^2 + 2397^2 .

It is an emirp because it is prime and its reverse (33602281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18220633 - 2⁹ = 18220121 is a prime.

It is equal to p_1164454 and since 18220633 and 1164454 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 18220598 and 18220607.

It is not a weakly prime, because it can be changed into another prime (18220637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9110316 + 9110317.

It is an arithmetic number, because the mean of its divisors is an integer number (9110317).

Almost surely, 2^18220633 is an apocalyptic number.

It is an amenable number.

18220633 is a deficient number, since it is larger than the sum of its proper divisors (1).

18220633 is an equidigital number, since it uses as much as digits as its factorization.

18220633 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 18220633 is about 4268.5633414534. The cubic root of 18220633 is about 263.1405755248.

The spelling of 18220633 in words is "eighteen million, two hundred twenty thousand, six hundred thirty-three".