21663410412506 has 16 divisors (see below), whose sum is σ = 34257033354240. Its totient is φ = 10259267798640.

The previous prime is 21663410412499. The next prime is 21663410412509. The reversal of 21663410412506 is 60521401436612.

It is not an unprimeable number, because it can be changed into a prime (21663410412509) 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 7 ways as a sum of consecutive naturals, for example, 3717123101 + ... + 3717128928.

It is an arithmetic number, because the mean of its divisors is an integer number (2141064584640).

Almost surely, 2^{21663410412506} is an apocalyptic number.

21663410412506 is a deficient number, since it is larger than the sum of its proper divisors (12593622941734).

21663410412506 is a wasteful number, since it uses less digits than its factorization.

21663410412506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7434252109.

The product of its (nonzero) digits is 207360, while the sum is 41.

The spelling of 21663410412506 in words is "twenty-one trillion, six hundred sixty-three billion, four hundred ten million, four hundred twelve thousand, five hundred six".