21449628 has 36 divisors (see below), whose sum is σ = 54381600. Its totient is φ = 7128576.

The previous prime is 21449621. The next prime is 21449629. The reversal of 21449628 is 82694412.

21449628 is a `hidden beast` number, since 21 + 4 + 4 + 9 + 628 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21449592 and 21449601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21449621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15501 + ... + 16827.

It is an arithmetic number, because the mean of its divisors is an integer number (1510600).

Almost surely, 2^21449628 is an apocalyptic number.

It is an amenable number.

21449628 is an abundant number, since it is smaller than the sum of its proper divisors (32931972).

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

21449628 is a wasteful number, since it uses less digits than its factorization.

21449628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1786 (or 1781 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 21449628 is about 4631.3743100726. The cubic root of 21449628 is about 277.8475606130.

The spelling of 21449628 in words is "twenty-one million, four hundred forty-nine thousand, six hundred twenty-eight".