20139999 has 16 divisors (see below), whose sum is σ = 29735040. Its totient is φ = 12022560.

The previous prime is 20139997. The next prime is 20140027. The reversal of 20139999 is 99993102.

It is a happy number.

It is not a de Polignac number, because 20139999 - 2¹ = 20139997 is a prime.

20139999 is a modest number, since divided by 9999 gives 2013 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 20139999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20139991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2344 + ... + 6765.

It is an arithmetic number, because the mean of its divisors is an integer number (1858440).

Almost surely, 2^20139999 is an apocalyptic number.

20139999 is a deficient number, since it is larger than the sum of its proper divisors (9595041).

20139999 is a wasteful number, since it uses less digits than its factorization.

20139999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9190.

The product of its (nonzero) digits is 39366, while the sum is 42.

The square root of 20139999 is about 4487.7610230492. The cubic root of 20139999 is about 272.0736491379.

The spelling of 20139999 in words is "twenty million, one hundred thirty-nine thousand, nine hundred ninety-nine".