20381688 has 24 divisors (see below), whose sum is σ = 55200600. Its totient is φ = 6793872.

The previous prime is 20381677. The next prime is 20381689. The reversal of 20381688 is 88618302.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20381689) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 141468 + ... + 141611.

It is an arithmetic number, because the mean of its divisors is an integer number (2300025).

Almost surely, 2^20381688 is an apocalyptic number.

It is an amenable number.

20381688 is an abundant number, since it is smaller than the sum of its proper divisors (34818912).

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

20381688 is a wasteful number, since it uses less digits than its factorization.

20381688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283091 (or 283084 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 20381688 is about 4514.6082886558. The cubic root of 20381688 is about 273.1576596071.

The spelling of 20381688 in words is "twenty million, three hundred eighty-one thousand, six hundred eighty-eight".