18019540 has 48 divisors (see below), whose sum is σ = 47182464. Its totient is φ = 5616000.

The previous prime is 18019531. The next prime is 18019559. The reversal of 18019540 is 4591081.

It is a happy number.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 18019499 and 18019508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4311 + ... + 7390.

It is an arithmetic number, because the mean of its divisors is an integer number (982968).

Almost surely, 2^18019540 is an apocalyptic number.

18019540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18019540 is an abundant number, since it is smaller than the sum of its proper divisors (29162924).

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

18019540 is a wasteful number, since it uses less digits than its factorization.

18019540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11728 (or 11726 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 18019540 is about 4244.9428735850. The cubic root of 18019540 is about 262.1689371391.

The spelling of 18019540 in words is "eighteen million, nineteen thousand, five hundred forty".