21616361654243 has 4 divisors (see below), whose sum is σ = 21839210743560. Its totient is φ = 21393512564928.

The previous prime is 21616361654213. The next prime is 21616361654323. The reversal of 21616361654243 is 34245616361612.

It is a happy number.

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 21616361654243 - 2¹⁸ = 21616361392099 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21616361654191 and 21616361654200.

It is not an unprimeable number, because it can be changed into a prime (21616361654213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111424544513 + ... + 111424544706.

It is an arithmetic number, because the mean of its divisors is an integer number (5459802685890).

Almost surely, 2^{21616361654243} is an apocalyptic number.

21616361654243 is a deficient number, since it is larger than the sum of its proper divisors (222849089317).

21616361654243 is an equidigital number, since it uses as much as digits as its factorization.

21616361654243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222849089316.

The product of its digits is 3732480, while the sum is 50.

The spelling of 21616361654243 in words is "twenty-one trillion, six hundred sixteen billion, three hundred sixty-one million, six hundred fifty-four thousand, two hundred forty-three".