21840616646063 has 4 divisors (see below), whose sum is σ = 21840628193760. Its totient is φ = 21840605098368.

The previous prime is 21840616646039. The next prime is 21840616646081. The reversal of 21840616646063 is 36064661604812.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21840616646063 - 2¹² = 21840616641967 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21840616645996 and 21840616646014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21840616646003) 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, 2199095 + ... + 6965432.

It is an arithmetic number, because the mean of its divisors is an integer number (5460157048440).

Almost surely, 2^{21840616646063} is an apocalyptic number.

21840616646063 is a deficient number, since it is larger than the sum of its proper divisors (11547697).

21840616646063 is an equidigital number, since it uses as much as digits as its factorization.

21840616646063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11547696.

The product of its (nonzero) digits is 5971968, while the sum is 53.

The spelling of 21840616646063 in words is "twenty-one trillion, eight hundred forty billion, six hundred sixteen million, six hundred forty-six thousand, sixty-three".