18081780 has 24 divisors (see below), whose sum is σ = 50629152. Its totient is φ = 4821792.

The previous prime is 18081769. The next prime is 18081781. The reversal of 18081780 is 8718081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18081781) 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, 150622 + ... + 150741.

It is an arithmetic number, because the mean of its divisors is an integer number (2109548).

Almost surely, 2^18081780 is an apocalyptic number.

18081780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18081780 is an abundant number, since it is smaller than the sum of its proper divisors (32547372).

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

18081780 is a wasteful number, since it uses less digits than its factorization.

18081780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301375 (or 301373 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 33.

The square root of 18081780 is about 4252.2676303356. The cubic root of 18081780 is about 262.4704365799.

The spelling of 18081780 in words is "eighteen million, eighty-one thousand, seven hundred eighty".