21138846 has 8 divisors (see below), whose sum is σ = 42277704. Its totient is φ = 7046280.

The previous prime is 21138823. The next prime is 21138847. The reversal of 21138846 is 64883112.

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

21138846 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21138847) 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, 1761565 + ... + 1761576.

It is an arithmetic number, because the mean of its divisors is an integer number (5284713).

Almost surely, 2^21138846 is an apocalyptic number.

21138846 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.

21138846 is a wasteful number, since it uses less digits than its factorization.

21138846 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3523146.

The product of its digits is 9216, while the sum is 33.

The square root of 21138846 is about 4597.7000772125. The cubic root of 21138846 is about 276.4991230882.

The spelling of 21138846 in words is "twenty-one million, one hundred thirty-eight thousand, eight hundred forty-six".