18509780418 has 16 divisors (see below), whose sum is σ = 37378975296. Its totient is φ = 6110024400.

The previous prime is 18509780417. The next prime is 18509780437. The reversal of 18509780418 is 81408790581.

It is a happy number.

It is a super-2 number, since 2×18509780418² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18509780417) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14974933 + ... + 14976168.

It is an arithmetic number, because the mean of its divisors is an integer number (2336185956).

Almost surely, 2^18509780418 is an apocalyptic number.

18509780418 is an abundant number, since it is smaller than the sum of its proper divisors (18869194878).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18509780418 is a wasteful number, since it uses less digits than its factorization.

18509780418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29951209.

The product of its (nonzero) digits is 645120, while the sum is 51.

The spelling of 18509780418 in words is "eighteen billion, five hundred nine million, seven hundred eighty thousand, four hundred eighteen".