21026736 has 40 divisors (see below), whose sum is σ = 60355760. Its totient is φ = 7008768.

The previous prime is 21026717. The next prime is 21026741. The reversal of 21026736 is 63762012.

It is a happy number.

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 7 ways as a sum of consecutive naturals, for example, 23905 + ... + 24768.

It is an arithmetic number, because the mean of its divisors is an integer number (1508894).

Almost surely, 2^21026736 is an apocalyptic number.

It is an amenable number.

21026736 is an abundant number, since it is smaller than the sum of its proper divisors (39329024).

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

21026736 is a wasteful number, since it uses less digits than its factorization.

21026736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48690 (or 48678 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 21026736 is about 4585.4919038201. The cubic root of 21026736 is about 276.0094514722.

Adding to 21026736 its reverse (63762012), we get a palindrome (84788748).

The spelling of 21026736 in words is "twenty-one million, twenty-six thousand, seven hundred thirty-six".