21261242500641 has 48 divisors (see below), whose sum is σ = 37054810927680. Its totient is φ = 11572931064960.

The previous prime is 21261242500627. The next prime is 21261242500651. The reversal of 21261242500641 is 14600524216212.

21261242500641 is a `hidden beast` number, since 2 + 1 + 2 + 6 + 1 + 2 + 4 + 2 + 5 + 0 + 0 + 641 = 666.

It is not a de Polignac number, because 21261242500641 - 2⁶ = 21261242500577 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21261242500596 and 21261242500605.

It is not an unprimeable number, because it can be changed into a prime (21261242500601) 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 in 47 ways as a sum of consecutive naturals, for example, 223195651 + ... + 223290888.

It is an arithmetic number, because the mean of its divisors is an integer number (771975227660).

Almost surely, 2^{21261242500641} is an apocalyptic number.

It is an amenable number.

21261242500641 is a deficient number, since it is larger than the sum of its proper divisors (15793568427039).

21261242500641 is a wasteful number, since it uses less digits than its factorization.

21261242500641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446486606 (or 446486603 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

Adding to 21261242500641 its reverse (14600524216212), we get a palindrome (35861766716853).

The spelling of 21261242500641 in words is "twenty-one trillion, two hundred sixty-one billion, two hundred forty-two million, five hundred thousand, six hundred forty-one".