18220307 has 6 divisors (see below), whose sum is σ = 21195108. Its totient is φ = 15617364.

The previous prime is 18220291. The next prime is 18220313. The reversal of 18220307 is 70302281.

It is not a de Polignac number, because 18220307 - 2⁴ = 18220291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18220337) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 185873 + ... + 185970.

It is an arithmetic number, because the mean of its divisors is an integer number (3532518).

Almost surely, 2^18220307 is an apocalyptic number.

18220307 is a deficient number, since it is larger than the sum of its proper divisors (2974801).

18220307 is an equidigital number, since it uses as much as digits as its factorization.

18220307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371857 (or 371850 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 18220307 is about 4268.5251551326. The cubic root of 18220307 is about 263.1390061622.

Adding to 18220307 its reverse (70302281), we get a palindrome (88522588).

The spelling of 18220307 in words is "eighteen million, two hundred twenty thousand, three hundred seven".