18742640 has 40 divisors (see below), whose sum is σ = 49803360. Its totient is φ = 6425856.

The previous prime is 18742627. The next prime is 18742643. The reversal of 18742640 is 4624781.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 18742597 and 18742606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18742643) 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, 16175 + ... + 17294.

It is an arithmetic number, because the mean of its divisors is an integer number (1245084).

Almost surely, 2^18742640 is an apocalyptic number.

18742640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18742640 is an abundant number, since it is smaller than the sum of its proper divisors (31060720).

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

18742640 is a wasteful number, since it uses less digits than its factorization.

18742640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33489 (or 33483 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 32.

The square root of 18742640 is about 4329.2770759100. The cubic root of 18742640 is about 265.6298770039.

The spelling of 18742640 in words is "eighteen million, seven hundred forty-two thousand, six hundred forty".