21785248 has 24 divisors (see below), whose sum is σ = 45148320. Its totient is φ = 10319040.

The previous prime is 21785243. The next prime is 21785249. The reversal of 21785248 is 84258712.

It is not an unprimeable number, because it can be changed into a prime (21785243) 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, 17308 + ... + 18523.

It is an arithmetic number, because the mean of its divisors is an integer number (1881180).

Almost surely, 2^21785248 is an apocalyptic number.

It is an amenable number.

21785248 is an abundant number, since it is smaller than the sum of its proper divisors (23363072).

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

21785248 is a wasteful number, since it uses less digits than its factorization.

21785248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35860 (or 35852 counting only the distinct ones).

The product of its digits is 35840, while the sum is 37.

The square root of 21785248 is about 4667.4669789941. The cubic root of 21785248 is about 279.2892176078.

The spelling of 21785248 in words is "twenty-one million, seven hundred eighty-five thousand, two hundred forty-eight".