19691139 has 8 divisors (see below), whose sum is σ = 28274512. Its totient is φ = 12117600.

The previous prime is 19691129. The next prime is 19691149. The reversal of 19691139 is 93119691.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (19691129) and next prime (19691149).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19691139 - 2⁸ = 19690883 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 504901 = 19691139 / (1 + 9 + 6 + 9 + 1 + 1 + 3 + 9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19691097 and 19691106.

It is not an unprimeable number, because it can be changed into a prime (19691129) 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, 252412 + ... + 252489.

It is an arithmetic number, because the mean of its divisors is an integer number (3534314).

Almost surely, 2^19691139 is an apocalyptic number.

19691139 is a deficient number, since it is larger than the sum of its proper divisors (8583373).

19691139 is a wasteful number, since it uses less digits than its factorization.

19691139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 504917.

The product of its digits is 13122, while the sum is 39.

The square root of 19691139 is about 4437.4698872218. The cubic root of 19691139 is about 270.0372102351.

The spelling of 19691139 in words is "nineteen million, six hundred ninety-one thousand, one hundred thirty-nine".