18218138265601 has 4 divisors (see below), whose sum is σ = 18218745344304. Its totient is φ = 18217531186900.

The previous prime is 18218138265583. The next prime is 18218138265611. The reversal of 18218138265601 is 10656283181281.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18218138265601 - 2²³ = 18218129876993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18218138265611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 303494335 + ... + 303554356.

It is an arithmetic number, because the mean of its divisors is an integer number (4554686336076).

Almost surely, 2^{18218138265601} is an apocalyptic number.

It is an amenable number.

18218138265601 is a deficient number, since it is larger than the sum of its proper divisors (607078703).

18218138265601 is an equidigital number, since it uses as much as digits as its factorization.

18218138265601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 607078702.

The product of its (nonzero) digits is 1105920, while the sum is 52.

The spelling of 18218138265601 in words is "eighteen trillion, two hundred eighteen billion, one hundred thirty-eight million, two hundred sixty-five thousand, six hundred one".