21406230563 has 2 divisors, whose sum is σ = 21406230564. Its totient is φ = 21406230562.

The previous prime is 21406230539. The next prime is 21406230589. The reversal of 21406230563 is 36503260412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21406230563 - 2⁶ = 21406230499 is a prime.

It is not a weakly prime, because it can be changed into another prime (21406230523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10703115281 + 10703115282.

It is an arithmetic number, because the mean of its divisors is an integer number (10703115282).

Almost surely, 2^21406230563 is an apocalyptic number.

21406230563 is a deficient number, since it is larger than the sum of its proper divisors (1).

21406230563 is an equidigital number, since it uses as much as digits as its factorization.

21406230563 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 32.

Adding to 21406230563 its reverse (36503260412), we get a palindrome (57909490975).

The spelling of 21406230563 in words is "twenty-one billion, four hundred six million, two hundred thirty thousand, five hundred sixty-three".