21061616616063 has 20 divisors (see below), whose sum is σ = 31841480195448. Its totient is φ = 13871908128240.

The previous prime is 21061616616037. The next prime is 21061616616071. The reversal of 21061616616063 is 36061661616012.

21061616616063 is a `hidden beast` number, since 2 + 1 + 0 + 6 + 16 + 16 + 616 + 0 + 6 + 3 = 666.

It is not a de Polignac number, because 21061616616063 - 2¹² = 21061616611967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21061616616013) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1566378568 + ... + 1566392013.

Almost surely, 2^{21061616616063} is an apocalyptic number.

21061616616063 is a deficient number, since it is larger than the sum of its proper divisors (10779863579385).

21061616616063 is an equidigital number, since it uses as much as digits as its factorization.

21061616616063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3132770676 (or 3132770667 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The spelling of 21061616616063 in words is "twenty-one trillion, sixty-one billion, six hundred sixteen million, six hundred sixteen thousand, sixty-three".