21663545650263 has 12 divisors (see below), whose sum is σ = 34136496176328. Its totient is φ = 13129421606160.

The previous prime is 21663545650207. The next prime is 21663545650277. The reversal of 21663545650263 is 36205654536612.

It is a happy number.

21663545650263 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 3 + 54 + 565 + 0 + 26 + 3 = 666.

It is not a de Polignac number, because 21663545650263 - 2⁸ = 21663545650007 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21663545655263) 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 11 ways as a sum of consecutive naturals, for example, 109411846620 + ... + 109411846817.

It is an arithmetic number, because the mean of its divisors is an integer number (2844708014694).

Almost surely, 2^{21663545650263} is an apocalyptic number.

21663545650263 is a deficient number, since it is larger than the sum of its proper divisors (12472950526065).

21663545650263 is a wasteful number, since it uses less digits than its factorization.

21663545650263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218823693454 (or 218823693451 counting only the distinct ones).

The product of its (nonzero) digits is 23328000, while the sum is 54.

The spelling of 21663545650263 in words is "twenty-one trillion, six hundred sixty-three billion, five hundred forty-five million, six hundred fifty thousand, two hundred sixty-three".