19931139 has 6 divisors (see below), whose sum is σ = 28789436. Its totient is φ = 13287420.

The previous prime is 19931129. The next prime is 19931143. The reversal of 19931139 is 93113991.

It is not a de Polignac number, because 19931139 - 2⁷ = 19931011 is a prime.

It is a nude number because it is divisible by every one of its digits.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19931129) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1107277 + ... + 1107294.

Almost surely, 2^19931139 is an apocalyptic number.

19931139 is a deficient number, since it is larger than the sum of its proper divisors (8858297).

19931139 is a wasteful number, since it uses less digits than its factorization.

19931139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2214577 (or 2214574 counting only the distinct ones).

The product of its digits is 6561, while the sum is 36.

The square root of 19931139 is about 4464.4304227975. The cubic root of 19931139 is about 271.1298742513.

The spelling of 19931139 in words is "nineteen million, nine hundred thirty-one thousand, one hundred thirty-nine".