18542640 has 40 divisors (see below), whose sum is σ = 57482928. Its totient is φ = 4944640.

The previous prime is 18542627. The next prime is 18542647. The reversal of 18542640 is 4624581.

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

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 18542598 and 18542607.

It is not an unprimeable number, because it can be changed into a prime (18542647) 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, 38391 + ... + 38870.

Almost surely, 2^18542640 is an apocalyptic number.

18542640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18542640 is an abundant number, since it is smaller than the sum of its proper divisors (38940288).

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

18542640 is a wasteful number, since it uses less digits than its factorization.

18542640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77277 (or 77271 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 18542640 is about 4306.1165799360. The cubic root of 18542640 is about 264.6816635504.

The spelling of 18542640 in words is "eighteen million, five hundred forty-two thousand, six hundred forty".