21521148 has 48 divisors (see below), whose sum is σ = 57671040. Its totient is φ = 6177600.

The previous prime is 21521141. The next prime is 21521183. The reversal of 21521148 is 84112512.

It is a super-2 number, since 2×21521148² = 926319622475808, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21521141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1783 + ... + 6798.

It is an arithmetic number, because the mean of its divisors is an integer number (1201480).

Almost surely, 2^21521148 is an apocalyptic number.

It is an amenable number.

21521148 is an abundant number, since it is smaller than the sum of its proper divisors (36149892).

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

21521148 is a wasteful number, since it uses less digits than its factorization.

21521148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8618 (or 8616 counting only the distinct ones).

The product of its digits is 640, while the sum is 24.

The square root of 21521148 is about 4639.0891347332. The cubic root of 21521148 is about 278.1560292444.

The spelling of 21521148 in words is "twenty-one million, five hundred twenty-one thousand, one hundred forty-eight".