21240748 has 6 divisors (see below), whose sum is σ = 37171316. Its totient is φ = 10620372.

The previous prime is 21240743. The next prime is 21240761. The reversal of 21240748 is 84704212.

It is not an unprimeable number, because it can be changed into a prime (21240743) 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 as a sum of consecutive naturals, namely, 2655090 + ... + 2655097.

Almost surely, 2^21240748 is an apocalyptic number.

It is an amenable number.

21240748 is a deficient number, since it is larger than the sum of its proper divisors (15930568).

21240748 is a wasteful number, since it uses less digits than its factorization.

21240748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5310191 (or 5310189 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 21240748 is about 4608.7685990946. The cubic root of 21240748 is about 276.9427086351.

The spelling of 21240748 in words is "twenty-one million, two hundred forty thousand, seven hundred forty-eight".