19989739 has 16 divisors (see below), whose sum is σ = 26390016. Its totient is φ = 14659200.

The previous prime is 19989727. The next prime is 19989743. The reversal of 19989739 is 93798991.

It is a cyclic number.

It is not a de Polignac number, because 19989739 - 2⁵ = 19989707 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19989739.

It is not an unprimeable number, because it can be changed into a prime (19989709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6327 + ... + 8944.

It is an arithmetic number, because the mean of its divisors is an integer number (1649376).

Almost surely, 2^19989739 is an apocalyptic number.

19989739 is a deficient number, since it is larger than the sum of its proper divisors (6400277).

19989739 is a wasteful number, since it uses less digits than its factorization.

19989739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15306.

The product of its digits is 1102248, while the sum is 55.

The square root of 19989739 is about 4470.9885931413. The cubic root of 19989739 is about 271.3953326532.

The spelling of 19989739 in words is "nineteen million, nine hundred eighty-nine thousand, seven hundred thirty-nine".