21616024216145 has 4 divisors (see below), whose sum is σ = 25939229059380. Its totient is φ = 17292819372912.

The previous prime is 21616024216109. The next prime is 21616024216217. The reversal of 21616024216145 is 54161242061612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 9672392342209 + 11943631873936 = 3110047^2 + 3455956^2 .

It is a cyclic number.

It is not a de Polignac number, because 21616024216145 - 2⁴⁴ = 4023838171729 is a prime.

It is a super-2 number, since 2×21616024216145² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2161602421610 + ... + 2161602421619.

It is an arithmetic number, because the mean of its divisors is an integer number (6484807264845).

Almost surely, 2^{21616024216145} is an apocalyptic number.

It is an amenable number.

21616024216145 is a deficient number, since it is larger than the sum of its proper divisors (4323204843235).

21616024216145 is an equidigital number, since it uses as much as digits as its factorization.

21616024216145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4323204843234.

The product of its (nonzero) digits is 138240, while the sum is 41.

Adding to 21616024216145 its reverse (54161242061612), we get a palindrome (75777266277757).

The spelling of 21616024216145 in words is "twenty-one trillion, six hundred sixteen billion, twenty-four million, two hundred sixteen thousand, one hundred forty-five".