21107751563 has 2 divisors, whose sum is σ = 21107751564. Its totient is φ = 21107751562.

The previous prime is 21107751557. The next prime is 21107751589. The reversal of 21107751563 is 36515770112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21107751563 - 2⁶ = 21107751499 is a prime.

It is not a weakly prime, because it can be changed into another prime (21107751503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10553875781 + 10553875782.

It is an arithmetic number, because the mean of its divisors is an integer number (10553875782).

Almost surely, 2^21107751563 is an apocalyptic number.

21107751563 is a deficient number, since it is larger than the sum of its proper divisors (1).

21107751563 is an equidigital number, since it uses as much as digits as its factorization.

21107751563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 44100, while the sum is 38.

The spelling of 21107751563 in words is "twenty-one billion, one hundred seven million, seven hundred fifty-one thousand, five hundred sixty-three".