21878152 has 16 divisors (see below), whose sum is σ = 42805440. Its totient is φ = 10463376.

The previous prime is 21878149. The next prime is 21878243. The reversal of 21878152 is 25187812.

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, 59268 + ... + 59635.

It is an arithmetic number, because the mean of its divisors is an integer number (2675340).

Almost surely, 2^21878152 is an apocalyptic number.

It is an amenable number.

21878152 is a deficient number, since it is larger than the sum of its proper divisors (20927288).

21878152 is a wasteful number, since it uses less digits than its factorization.

21878152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118932 (or 118928 counting only the distinct ones).

The product of its digits is 8960, while the sum is 34.

The square root of 21878152 is about 4677.4086843037. The cubic root of 21878152 is about 279.6856676659.

The spelling of 21878152 in words is "twenty-one million, eight hundred seventy-eight thousand, one hundred fifty-two".