18019780 has 24 divisors (see below), whose sum is σ = 38485440. Its totient is φ = 7085280.

The previous prime is 18019739. The next prime is 18019789. The reversal of 18019780 is 8791081.

It is not an unprimeable number, because it can be changed into a prime (18019789) 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, 6456 + ... + 8815.

It is an arithmetic number, because the mean of its divisors is an integer number (1603560).

Almost surely, 2^18019780 is an apocalyptic number.

18019780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18019780 is an abundant number, since it is smaller than the sum of its proper divisors (20465660).

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

18019780 is a wasteful number, since it uses less digits than its factorization.

18019780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15339 (or 15337 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 34.

The square root of 18019780 is about 4244.9711424225. The cubic root of 18019780 is about 262.1701010657.

The spelling of 18019780 in words is "eighteen million, nineteen thousand, seven hundred eighty".