18885640 has 32 divisors (see below), whose sum is σ = 44993880. Its totient is φ = 7109632.

The previous prime is 18885631. The next prime is 18885673. The reversal of 18885640 is 4658881.

It can be written as a sum of positive squares in 4 ways, for example, as 17757796 + 1127844 = 4214^2 + 1062^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 18885593 and 18885602.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13207 + ... + 14566.

Almost surely, 2^18885640 is an apocalyptic number.

18885640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18885640 is an abundant number, since it is smaller than the sum of its proper divisors (26108240).

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

18885640 is a wasteful number, since it uses less digits than its factorization.

18885640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27801 (or 27797 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 40.

The square root of 18885640 is about 4345.7611531238. The cubic root of 18885640 is about 266.3037215175.

The spelling of 18885640 in words is "eighteen million, eight hundred eighty-five thousand, six hundred forty".