20187940 has 24 divisors (see below), whose sum is σ = 43542072. Its totient is φ = 7856640.

The previous prime is 20187917. The next prime is 20187961. The reversal of 20187940 is 4978102.

It can be written as a sum of positive squares in 4 ways, for example, as 8202496 + 11985444 = 2864^2 + 3462^2 .

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, 12901 + ... + 14380.

It is an arithmetic number, because the mean of its divisors is an integer number (1814253).

Almost surely, 2^20187940 is an apocalyptic number.

20187940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20187940 is an abundant number, since it is smaller than the sum of its proper divisors (23354132).

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

20187940 is a wasteful number, since it uses less digits than its factorization.

20187940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27327 (or 27325 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 20187940 is about 4493.0991531459. The cubic root of 20187940 is about 272.2893583006.

The spelling of 20187940 in words is "twenty million, one hundred eighty-seven thousand, nine hundred forty".