21010126563 has 12 divisors (see below), whose sum is σ = 30391888488. Its totient is φ = 13986476640.

The previous prime is 21010126559. The next prime is 21010126597. The reversal of 21010126563 is 36562101012.

21010126563 is a `hidden beast` number, since 2 + 1 + 0 + 1 + 0 + 1 + 2 + 656 + 3 = 666.

It is not a de Polignac number, because 21010126563 - 2² = 21010126559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21010126513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1682970 + ... + 1695407.

It is an arithmetic number, because the mean of its divisors is an integer number (2532657374).

Almost surely, 2^21010126563 is an apocalyptic number.

21010126563 is a deficient number, since it is larger than the sum of its proper divisors (9381761925).

21010126563 is a wasteful number, since it uses less digits than its factorization.

21010126563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3379074 (or 3379071 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

Adding to 21010126563 its reverse (36562101012), we get a palindrome (57572227575).

The spelling of 21010126563 in words is "twenty-one billion, ten million, one hundred twenty-six thousand, five hundred sixty-three".