21663163533465 has 96 divisors (see below), whose sum is σ = 39147056676000. Its totient is φ = 11068498022400.

The previous prime is 21663163533463. The next prime is 21663163533509. The reversal of 21663163533465 is 56433536136612.

21663163533465 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 3 + 1 + 63 + 533 + 46 + 5 = 666.

It can be written as a sum of positive squares in 16 ways, for example, as 15476442548121 + 6186720985344 = 3934011^2 + 2487312^2 .

It is not a de Polignac number, because 21663163533465 - 2¹ = 21663163533463 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21663163533463) 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 in 95 ways as a sum of consecutive naturals, for example, 182135515 + ... + 182254415.

It is an arithmetic number, because the mean of its divisors is an integer number (407781840375).

Almost surely, 2^{21663163533465} is an apocalyptic number.

It is an amenable number.

21663163533465 is a deficient number, since it is larger than the sum of its proper divisors (17483893142535).

21663163533465 is a wasteful number, since it uses less digits than its factorization.

21663163533465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120027 (or 120024 counting only the distinct ones).

The product of its digits is 20995200, while the sum is 54.

The spelling of 21663163533465 in words is "twenty-one trillion, six hundred sixty-three billion, one hundred sixty-three million, five hundred thirty-three thousand, four hundred sixty-five".