20388887 has 8 divisors (see below), whose sum is σ = 20996976. Its totient is φ = 19783872.

The previous prime is 20388883. The next prime is 20388947. The reversal of 20388887 is 78888302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20388887 - 2² = 20388883 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20388883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23363 + ... + 24219.

It is an arithmetic number, because the mean of its divisors is an integer number (2624622).

Almost surely, 2^20388887 is an apocalyptic number.

20388887 is a deficient number, since it is larger than the sum of its proper divisors (608089).

20388887 is an equidigital number, since it uses as much as digits as its factorization.

20388887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1537.

The product of its (nonzero) digits is 172032, while the sum is 44.

The square root of 20388887 is about 4515.4055188875. The cubic root of 20388887 is about 273.1898164221.

The spelling of 20388887 in words is "twenty million, three hundred eighty-eight thousand, eight hundred eighty-seven".