18640540 has 24 divisors (see below), whose sum is σ = 39386592. Its totient is φ = 7410240.

The previous prime is 18640513. The next prime is 18640541. The reversal of 18640540 is 4504681.

It is a junction number, because it is equal to n+sod(n) for n = 18640499 and 18640508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18640541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 550 + ... + 6130.

It is an arithmetic number, because the mean of its divisors is an integer number (1641108).

Almost surely, 2^18640540 is an apocalyptic number.

18640540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18640540 is an abundant number, since it is smaller than the sum of its proper divisors (20746052).

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

18640540 is a wasteful number, since it uses less digits than its factorization.

18640540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5757 (or 5755 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 18640540 is about 4317.4691660740. The cubic root of 18640540 is about 265.1466614298.

The spelling of 18640540 in words is "eighteen million, six hundred forty thousand, five hundred forty".