21026763 has 8 divisors (see below), whose sum is σ = 31150800. Its totient is φ = 14017824.

The previous prime is 21026741. The next prime is 21026777. The reversal of 21026763 is 36762012.

It is a happy number.

It is not a de Polignac number, because 21026763 - 2⁹ = 21026251 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 778769 = 21026763 / (2 + 1 + 0 + 2 + 6 + 7 + 6 + 3).

It is not an unprimeable number, because it can be changed into a prime (21026063) 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 7 ways as a sum of consecutive naturals, for example, 389358 + ... + 389411.

It is an arithmetic number, because the mean of its divisors is an integer number (3893850).

Almost surely, 2^21026763 is an apocalyptic number.

21026763 is a deficient number, since it is larger than the sum of its proper divisors (10124037).

21026763 is an equidigital number, since it uses as much as digits as its factorization.

21026763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778778 (or 778772 counting only the distinct ones).

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

The square root of 21026763 is about 4585.4948478872. The cubic root of 21026763 is about 276.0095696115.

Adding to 21026763 its reverse (36762012), we get a palindrome (57788775).

The spelling of 21026763 in words is "twenty-one million, twenty-six thousand, seven hundred sixty-three".