18380121705 has 48 divisors (see below), whose sum is σ = 34816541760. Its totient is φ = 8895830400.

The previous prime is 18380121689. The next prime is 18380121707. The reversal of 18380121705 is 50712108381.

It is not a de Polignac number, because 18380121705 - 2⁴ = 18380121689 is a prime.

It is a super-2 number, since 2×18380121705² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18380121705.

It is not an unprimeable number, because it can be changed into a prime (18380121707) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 250131 + ... + 315159.

It is an arithmetic number, because the mean of its divisors is an integer number (725344620).

Almost surely, 2^18380121705 is an apocalyptic number.

18380121705 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18380121705 is a deficient number, since it is larger than the sum of its proper divisors (16436420055).

18380121705 is a wasteful number, since it uses less digits than its factorization.

18380121705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65622 (or 65619 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 36.

The spelling of 18380121705 in words is "eighteen billion, three hundred eighty million, one hundred twenty-one thousand, seven hundred five".