21874638 has 8 divisors (see below), whose sum is σ = 43749288. Its totient is φ = 7291544.

The previous prime is 21874627. The next prime is 21874673. The reversal of 21874638 is 83647812.

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

21874638 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21874596 and 21874605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1822881 + ... + 1822892.

It is an arithmetic number, because the mean of its divisors is an integer number (5468661).

Almost surely, 2^21874638 is an apocalyptic number.

21874638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21874638 is a wasteful number, since it uses less digits than its factorization.

21874638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3645778.

The product of its digits is 64512, while the sum is 39.

The square root of 21874638 is about 4677.0330338795. The cubic root of 21874638 is about 279.6706927865.

The spelling of 21874638 in words is "twenty-one million, eight hundred seventy-four thousand, six hundred thirty-eight".