21086438 has 8 divisors (see below), whose sum is σ = 31789200. Its totient is φ = 10490040.

The previous prime is 21086431. The next prime is 21086453. The reversal of 21086438 is 83468012.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21086431) 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, 26093 + ... + 26888.

It is an arithmetic number, because the mean of its divisors is an integer number (3973650).

Almost surely, 2^21086438 is an apocalyptic number.

21086438 is a deficient number, since it is larger than the sum of its proper divisors (10702762).

21086438 is a wasteful number, since it uses less digits than its factorization.

21086438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53182.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 21086438 is about 4591.9971689887. The cubic root of 21086438 is about 276.2704326185.

The spelling of 21086438 in words is "twenty-one million, eighty-six thousand, four hundred thirty-eight".