18719437 has 4 divisors (see below), whose sum is σ = 20421216. Its totient is φ = 17017660.

The previous prime is 18719429. The next prime is 18719473. The reversal of 18719437 is 73491781.

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: 73491781 = 11 ⋅6681071.

It is not a de Polignac number, because 18719437 - 2³ = 18719429 is a prime.

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 18719437.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18719417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 850873 + ... + 850894.

It is an arithmetic number, because the mean of its divisors is an integer number (5105304).

Almost surely, 2^18719437 is an apocalyptic number.

It is an amenable number.

18719437 is a deficient number, since it is larger than the sum of its proper divisors (1701779).

18719437 is a wasteful number, since it uses less digits than its factorization.

18719437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1701778.

The product of its digits is 42336, while the sum is 40.

The square root of 18719437 is about 4326.5964683571. The cubic root of 18719437 is about 265.5202169777.

The spelling of 18719437 in words is "eighteen million, seven hundred nineteen thousand, four hundred thirty-seven".