21065404645163 has 8 divisors (see below), whose sum is σ = 21264095982960. Its totient is φ = 20866746981600.

The previous prime is 21065404645157. The next prime is 21065404645177. The reversal of 21065404645163 is 36154640456012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21065404645163 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21065404645463) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7160648 + ... + 9664661.

It is an arithmetic number, because the mean of its divisors is an integer number (2658011997870).

Almost surely, 2^{21065404645163} is an apocalyptic number.

21065404645163 is a deficient number, since it is larger than the sum of its proper divisors (198691337797).

21065404645163 is a wasteful number, since it uses less digits than its factorization.

21065404645163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16837117.

The product of its (nonzero) digits is 2073600, while the sum is 47.

The spelling of 21065404645163 in words is "twenty-one trillion, sixty-five billion, four hundred four million, six hundred forty-five thousand, one hundred sixty-three".