21967438 has 8 divisors (see below), whose sum is σ = 34383888. Its totient is φ = 10506144.

The previous prime is 21967433. The next prime is 21967441. The reversal of 21967438 is 83476912.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21967438.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21967433) 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, 238731 + ... + 238822.

It is an arithmetic number, because the mean of its divisors is an integer number (4297986).

Almost surely, 2^21967438 is an apocalyptic number.

21967438 is a deficient number, since it is larger than the sum of its proper divisors (12416450).

21967438 is a wasteful number, since it uses less digits than its factorization.

21967438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477578.

The product of its digits is 72576, while the sum is 40.

The square root of 21967438 is about 4686.9433536154. The cubic root of 21967438 is about 280.0656223743.

The spelling of 21967438 in words is "twenty-one million, nine hundred sixty-seven thousand, four hundred thirty-eight".