21481248 has 48 divisors (see below), whose sum is σ = 59361120. Its totient is φ = 6782976.

The previous prime is 21481231. The next prime is 21481259. The reversal of 21481248 is 84218412.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×21481248² = 922888031275008, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4065 + ... + 7712.

It is an arithmetic number, because the mean of its divisors is an integer number (1236690).

Almost surely, 2^21481248 is an apocalyptic number.

It is an amenable number.

21481248 is an abundant number, since it is smaller than the sum of its proper divisors (37879872).

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

21481248 is a wasteful number, since it uses less digits than its factorization.

21481248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11809 (or 11801 counting only the distinct ones).

The product of its digits is 4096, while the sum is 30.

The square root of 21481248 is about 4634.7867264848. The cubic root of 21481248 is about 277.9840233732.

The spelling of 21481248 in words is "twenty-one million, four hundred eighty-one thousand, two hundred forty-eight".