18001387780 has 12 divisors (see below), whose sum is σ = 37802914380. Its totient is φ = 7200555104.

The previous prime is 18001387763. The next prime is 18001387837. The reversal of 18001387780 is 8778310081.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6134335684 + 11867052096 = 78322^2 + 108936^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 450034675 + ... + 450034714.

It is an arithmetic number, because the mean of its divisors is an integer number (3150242865).

Almost surely, 2^18001387780 is an apocalyptic number.

18001387780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18001387780 is an abundant number, since it is smaller than the sum of its proper divisors (19801526600).

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

18001387780 is a wasteful number, since it uses less digits than its factorization.

18001387780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900069398 (or 900069396 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 43.

The spelling of 18001387780 in words is "eighteen billion, one million, three hundred eighty-seven thousand, seven hundred eighty".