21878200 has 24 divisors (see below), whose sum is σ = 50867280. Its totient is φ = 8751200.

The previous prime is 21878149. The next prime is 21878243. The reversal of 21878200 is 287812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 54496 + ... + 54895.

It is an arithmetic number, because the mean of its divisors is an integer number (2119470).

Almost surely, 2^21878200 is an apocalyptic number.

21878200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21878200 is an abundant number, since it is smaller than the sum of its proper divisors (28989080).

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

21878200 is a wasteful number, since it uses less digits than its factorization.

21878200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109407 (or 109398 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 21878200 is about 4677.4138153471. The cubic root of 21878200 is about 279.6858722063.

The spelling of 21878200 in words is "twenty-one million, eight hundred seventy-eight thousand, two hundred".