19691039 has 4 divisors (see below), whose sum is σ = 19731000. Its totient is φ = 19651080.

The previous prime is 19691017. The next prime is 19691051. The reversal of 19691039 is 93019691.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93019691 = 2339 ⋅39769.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19691039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19690993 and 19691011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19693039) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19232 + ... + 20229.

It is an arithmetic number, because the mean of its divisors is an integer number (4932750).

Almost surely, 2^19691039 is an apocalyptic number.

19691039 is a deficient number, since it is larger than the sum of its proper divisors (39961).

19691039 is an equidigital number, since it uses as much as digits as its factorization.

19691039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39960.

The product of its (nonzero) digits is 13122, while the sum is 38.

The square root of 19691039 is about 4437.4586195254. The cubic root of 19691039 is about 270.0367531130.

The spelling of 19691039 in words is "nineteen million, six hundred ninety-one thousand, thirty-nine".