18971438 has 8 divisors (see below), whose sum is σ = 29151360. Its totient is φ = 9254320.

The previous prime is 18971437. The next prime is 18971461. The reversal of 18971438 is 83417981.

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

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a junction number, because it is equal to n+sod(n) for n = 18971395 and 18971404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18971437) 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, 115598 + ... + 115761.

It is an arithmetic number, because the mean of its divisors is an integer number (3643920).

Almost surely, 2^18971438 is an apocalyptic number.

18971438 is a deficient number, since it is larger than the sum of its proper divisors (10179922).

18971438 is a wasteful number, since it uses less digits than its factorization.

18971438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231402.

The product of its digits is 48384, while the sum is 41.

The square root of 18971438 is about 4355.6214252389. The cubic root of 18971438 is about 266.7063874859.

The spelling of 18971438 in words is "eighteen million, nine hundred seventy-one thousand, four hundred thirty-eight".