21663546020653 has 16 divisors (see below), whose sum is σ = 23176878447744. Its totient is φ = 20177845542400.

The previous prime is 21663546020651. The next prime is 21663546020731. The reversal of 21663546020653 is 35602064536612.

It is a cyclic number.

It is not a de Polignac number, because 21663546020653 - 2¹ = 21663546020651 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21663546020597 and 21663546020606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21663546020651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16163248 + ... + 17452153.

It is an arithmetic number, because the mean of its divisors is an integer number (1448554902984).

Almost surely, 2^{21663546020653} is an apocalyptic number.

It is an amenable number.

21663546020653 is a deficient number, since it is larger than the sum of its proper divisors (1513332427091).

21663546020653 is a wasteful number, since it uses less digits than its factorization.

21663546020653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33615812.

The product of its (nonzero) digits is 4665600, while the sum is 49.

The spelling of 21663546020653 in words is "twenty-one trillion, six hundred sixty-three billion, five hundred forty-six million, twenty thousand, six hundred fifty-three".