19139997 has 4 divisors (see below), whose sum is σ = 25520000. Its totient is φ = 12759996.

The previous prime is 19139987. The next prime is 19139999. The reversal of 19139997 is 79993191.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79993191 = 3 ⋅26664397.

It is not a de Polignac number, because 19139997 - 2¹⁵ = 19107229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19139999) 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 3 ways as a sum of consecutive naturals, for example, 3189997 + ... + 3190002.

It is an arithmetic number, because the mean of its divisors is an integer number (6380000).

Almost surely, 2^19139997 is an apocalyptic number.

It is an amenable number.

19139997 is a deficient number, since it is larger than the sum of its proper divisors (6380003).

19139997 is an equidigital number, since it uses as much as digits as its factorization.

19139997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6380002.

The product of its digits is 137781, while the sum is 48.

The square root of 19139997 is about 4374.9282279827. The cubic root of 19139997 is about 267.4939446034.

The spelling of 19139997 in words is "nineteen million, one hundred thirty-nine thousand, nine hundred ninety-seven".