21879000 has 384 divisors, whose sum is σ = 91990080. Its totient is φ = 4608000.

The previous prime is 21878939. The next prime is 21879019. The reversal of 21879000 is 97812.

It is a congruent number.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 1286992 + ... + 1287008.

Almost surely, 2^21879000 is an apocalyptic number.

21879000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21879000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45995040).

21879000 is an abundant number, since it is smaller than the sum of its proper divisors (70111080).

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

21879000 is a wasteful number, since it uses less digits than its factorization.

21879000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 21879000 is about 4677.4993319080. The cubic root of 21879000 is about 279.6892811701.

It can be divided in two parts, 2187 and 9000, that multiplied together give a cube (19683000 = 270³).

The spelling of 21879000 in words is "twenty-one million, eight hundred seventy-nine thousand".