18780040 has 16 divisors (see below), whose sum is σ = 42255180. Its totient is φ = 7512000.

The previous prime is 18780011. The next prime is 18780043. The reversal of 18780040 is 4008781.

It can be written as a sum of positive squares in 2 ways, for example, as 16924996 + 1855044 = 4114^2 + 1362^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18779990 and 18780008.

It is not an unprimeable number, because it can be changed into a prime (18780043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234711 + ... + 234790.

Almost surely, 2^18780040 is an apocalyptic number.

18780040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18780040 is an abundant number, since it is smaller than the sum of its proper divisors (23475140).

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

18780040 is a wasteful number, since it uses less digits than its factorization.

18780040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469512 (or 469508 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 18780040 is about 4333.5943511132. The cubic root of 18780040 is about 265.8064433208.

The spelling of 18780040 in words is "eighteen million, seven hundred eighty thousand, forty".