21523063 has 2 divisors, whose sum is σ = 21523064. Its totient is φ = 21523062.

The previous prime is 21523049. The next prime is 21523069. The reversal of 21523063 is 36032512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21523063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21523069) 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 as a sum of consecutive naturals, namely, 10761531 + 10761532.

It is an arithmetic number, because the mean of its divisors is an integer number (10761532).

Almost surely, 2^21523063 is an apocalyptic number.

21523063 is a deficient number, since it is larger than the sum of its proper divisors (1).

21523063 is an equidigital number, since it uses as much as digits as its factorization.

21523063 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 22.

The square root of 21523063 is about 4639.2955284181. The cubic root of 21523063 is about 278.1642793154.

Adding to 21523063 its reverse (36032512), we get a palindrome (57555575).

The spelling of 21523063 in words is "twenty-one million, five hundred twenty-three thousand, sixty-three".