20388739 has 8 divisors (see below), whose sum is σ = 23931488. Its totient is φ = 17003520.

The previous prime is 20388737. The next prime is 20388749. The reversal of 20388739 is 93788302.

It is a happy number.

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 20388739 - 2¹ = 20388737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20388733) 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, 39102 + ... + 39619.

It is an arithmetic number, because the mean of its divisors is an integer number (2991436).

Almost surely, 2^20388739 is an apocalyptic number.

20388739 is a deficient number, since it is larger than the sum of its proper divisors (3542749).

20388739 is an equidigital number, since it uses as much as digits as its factorization.

20388739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78765.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 20388739 is about 4515.3891305180. The cubic root of 20388739 is about 273.1891554053.

The spelling of 20388739 in words is "twenty million, three hundred eighty-eight thousand, seven hundred thirty-nine".