21270763 has 2 divisors, whose sum is σ = 21270764. Its totient is φ = 21270762.

The previous prime is 21270751. The next prime is 21270773. The reversal of 21270763 is 36707212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21270763 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (21270713) 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, 10635381 + 10635382.

It is an arithmetic number, because the mean of its divisors is an integer number (10635382).

Almost surely, 2^21270763 is an apocalyptic number.

21270763 is a deficient number, since it is larger than the sum of its proper divisors (1).

21270763 is an equidigital number, since it uses as much as digits as its factorization.

21270763 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 28.

The square root of 21270763 is about 4612.0237423500. The cubic root of 21270763 is about 277.0730951776.

Adding to 21270763 its reverse (36707212), we get a palindrome (57977975).

The spelling of 21270763 in words is "twenty-one million, two hundred seventy thousand, seven hundred sixty-three".