21249704 has 16 divisors (see below), whose sum is σ = 45535200. Its totient is φ = 9106992.

The previous prime is 21249703. The next prime is 21249707. The reversal of 21249704 is 40794212.

It is not an unprimeable number, because it can be changed into a prime (21249703) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 189674 + ... + 189785.

It is an arithmetic number, because the mean of its divisors is an integer number (2845950).

Almost surely, 2^21249704 is an apocalyptic number.

It is an amenable number.

21249704 is an abundant number, since it is smaller than the sum of its proper divisors (24285496).

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

21249704 is a wasteful number, since it uses less digits than its factorization.

21249704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379472 (or 379468 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 21249704 is about 4609.7401228269. The cubic root of 21249704 is about 276.9816267621.

The spelling of 21249704 in words is "twenty-one million, two hundred forty-nine thousand, seven hundred four".