21840616646039 has 2 divisors, whose sum is σ = 21840616646040. Its totient is φ = 21840616646038.

The previous prime is 21840616646029. The next prime is 21840616646081. The reversal of 21840616646039 is 93064661604812.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21840616646039 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21840616646029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10920308323019 + 10920308323020.

It is an arithmetic number, because the mean of its divisors is an integer number (10920308323020).

Almost surely, 2^{21840616646039} is an apocalyptic number.

21840616646039 is a deficient number, since it is larger than the sum of its proper divisors (1).

21840616646039 is an equidigital number, since it uses as much as digits as its factorization.

21840616646039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8957952, while the sum is 56.

The spelling of 21840616646039 in words is "twenty-one trillion, eight hundred forty billion, six hundred sixteen million, six hundred forty-six thousand, thirty-nine".