20183640 has 32 divisors (see below), whose sum is σ = 60551280. Its totient is φ = 5382272.

The previous prime is 20183621. The next prime is 20183651. The reversal of 20183640 is 4638102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20183640.

It is a congruent number.

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, 83979 + ... + 84218.

Almost surely, 2^20183640 is an apocalyptic number.

20183640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20183640 is an abundant number, since it is smaller than the sum of its proper divisors (40367640).

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

20183640 is a wasteful number, since it uses less digits than its factorization.

20183640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168211 (or 168207 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 20183640 is about 4492.6206160770. The cubic root of 20183640 is about 272.2700245238.

The spelling of 20183640 in words is "twenty million, one hundred eighty-three thousand, six hundred forty".