21106663963 has 16 divisors (see below), whose sum is σ = 26318548224. Its totient is φ = 16444409760.

The previous prime is 21106663957. The next prime is 21106664129. The reversal of 21106663963 is 36936660112.

It is a cyclic number.

It is not a de Polignac number, because 21106663963 - 2⁹ = 21106663451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21106661963) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 692481 + ... + 722317.

It is an arithmetic number, because the mean of its divisors is an integer number (1644909264).

Almost surely, 2^21106663963 is an apocalyptic number.

21106663963 is a deficient number, since it is larger than the sum of its proper divisors (5211884261).

21106663963 is a wasteful number, since it uses less digits than its factorization.

21106663963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39042.

The product of its (nonzero) digits is 209952, while the sum is 43.

The spelling of 21106663963 in words is "twenty-one billion, one hundred six million, six hundred sixty-three thousand, nine hundred sixty-three".