21616118837 has 2 divisors, whose sum is σ = 21616118838. Its totient is φ = 21616118836.

The previous prime is 21616118807. The next prime is 21616118869. The reversal of 21616118837 is 73881161612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19939134436 + 1676984401 = 141206^2 + 40951^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21616118837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21616118807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10808059418 + 10808059419.

It is an arithmetic number, because the mean of its divisors is an integer number (10808059419).

Almost surely, 2^21616118837 is an apocalyptic number.

It is an amenable number.

21616118837 is a deficient number, since it is larger than the sum of its proper divisors (1).

21616118837 is an equidigital number, since it uses as much as digits as its factorization.

21616118837 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 44.

The spelling of 21616118837 in words is "twenty-one billion, six hundred sixteen million, one hundred eighteen thousand, eight hundred thirty-seven".