21615545046653 has 2 divisors, whose sum is σ = 21615545046654. Its totient is φ = 21615545046652.

The previous prime is 21615545046607. The next prime is 21615545046703. The reversal of 21615545046653 is 35664054551612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19102869886489 + 2512675160164 = 4370683^2 + 1585142^2 .

It is a cyclic number.

It is not a de Polignac number, because 21615545046653 - 2¹⁰ = 21615545045629 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21615545046595 and 21615545046604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21615545048653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10807772523326 + 10807772523327.

It is an arithmetic number, because the mean of its divisors is an integer number (10807772523327).

Almost surely, 2^{21615545046653} is an apocalyptic number.

It is an amenable number.

21615545046653 is a deficient number, since it is larger than the sum of its proper divisors (1).

21615545046653 is an equidigital number, since it uses as much as digits as its factorization.

21615545046653 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960000, while the sum is 53.

The spelling of 21615545046653 in words is "twenty-one trillion, six hundred fifteen billion, five hundred forty-five million, forty-six thousand, six hundred fifty-three".