19911139 has 8 divisors (see below), whose sum is σ = 20790000. Its totient is φ = 19045152.

The previous prime is 19911137. The next prime is 19911163. The reversal of 19911139 is 93111991.

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 19911139 - 2¹ = 19911137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19911137) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12 + ... + 6310.

It is an arithmetic number, because the mean of its divisors is an integer number (2598750).

Almost surely, 2^19911139 is an apocalyptic number.

19911139 is a deficient number, since it is larger than the sum of its proper divisors (878861).

19911139 is a wasteful number, since it uses less digits than its factorization.

19911139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6437.

The product of its digits is 2187, while the sum is 34.

The square root of 19911139 is about 4462.1899332054. The cubic root of 19911139 is about 271.0391550293.

The spelling of 19911139 in words is "nineteen million, nine hundred eleven thousand, one hundred thirty-nine".