21616006868051 has 4 divisors (see below), whose sum is σ = 21616527689352. Its totient is φ = 21615486046752.

The previous prime is 21616006868047. The next prime is 21616006868111. The reversal of 21616006868051 is 15086860061612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21616006868051 - 2² = 21616006868047 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21616006168051) 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 3 ways as a sum of consecutive naturals, for example, 260348390 + ... + 260431403.

It is an arithmetic number, because the mean of its divisors is an integer number (5404131922338).

Almost surely, 2^{21616006868051} is an apocalyptic number.

21616006868051 is a deficient number, since it is larger than the sum of its proper divisors (520821301).

21616006868051 is an equidigital number, since it uses as much as digits as its factorization.

21616006868051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520821300.

The product of its (nonzero) digits is 829440, while the sum is 50.

The spelling of 21616006868051 in words is "twenty-one trillion, six hundred sixteen billion, six million, eight hundred sixty-eight thousand, fifty-one".