19438919 has 4 divisors (see below), whose sum is σ = 20462040. Its totient is φ = 18415800.

The previous prime is 19438883. The next prime is 19438921. The reversal of 19438919 is 91983491.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19438919 - 2⁸ = 19438663 is a prime.

It is a super-2 number, since 2×19438919² = 755743143777122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19438919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19438999) 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, 511532 + ... + 511569.

It is an arithmetic number, because the mean of its divisors is an integer number (5115510).

Almost surely, 2^19438919 is an apocalyptic number.

19438919 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

19438919 is a deficient number, since it is larger than the sum of its proper divisors (1023121).

19438919 is a wasteful number, since it uses less digits than its factorization.

19438919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1023120.

The product of its digits is 69984, while the sum is 44.

The square root of 19438919 is about 4408.9589474160. The cubic root of 19438919 is about 268.8793007519.

The spelling of 19438919 in words is "nineteen million, four hundred thirty-eight thousand, nine hundred nineteen".