18221557307 has 8 divisors (see below), whose sum is σ = 18667992672. Its totient is φ = 17775217600.

The previous prime is 18221557303. The next prime is 18221557313. The reversal of 18221557307 is 70375512281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18221557307 - 2² = 18221557303 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18221557303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 500957 + ... + 536097.

It is an arithmetic number, because the mean of its divisors is an integer number (2333499084).

Almost surely, 2^18221557307 is an apocalyptic number.

18221557307 is a deficient number, since it is larger than the sum of its proper divisors (446435365).

18221557307 is a wasteful number, since it uses less digits than its factorization.

18221557307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47829.

The product of its (nonzero) digits is 117600, while the sum is 41.

The spelling of 18221557307 in words is "eighteen billion, two hundred twenty-one million, five hundred fifty-seven thousand, three hundred seven".