21147048 has 128 divisors (see below), whose sum is σ = 67132800. Its totient is φ = 6110208.

The previous prime is 21147037. The next prime is 21147059. The reversal of 21147048 is 84074112.

It is an interprime number because it is at equal distance from previous prime (21147037) and next prime (21147059).

It is a super-2 number, since 2×21147048² = 894395278228608, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 31 ways as a sum of consecutive naturals, for example, 47515 + ... + 47957.

It is an arithmetic number, because the mean of its divisors is an integer number (524475).

Almost surely, 2^21147048 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21147048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33566400).

21147048 is an abundant number, since it is smaller than the sum of its proper divisors (45985752).

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

21147048 is a wasteful number, since it uses less digits than its factorization.

21147048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488 (or 478 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 21147048 is about 4598.5919584151. The cubic root of 21147048 is about 276.5348795743.

The spelling of 21147048 in words is "twenty-one million, one hundred forty-seven thousand, forty-eight".