6661116097021 has 2 divisors, whose sum is σ = 6661116097022. Its totient is φ = 6661116097020.

The previous prime is 6661116097007. The next prime is 6661116097037. The reversal of 6661116097021 is 1207906111666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6660456377796 + 659719225 = 2580786^2 + 25685^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6661116097021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6661116797021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3330558048510 + 3330558048511.

It is an arithmetic number, because the mean of its divisors is an integer number (3330558048511).

Almost surely, 2^{6661116097021} is an apocalyptic number.

It is an amenable number.

6661116097021 is a deficient number, since it is larger than the sum of its proper divisors (1).

6661116097021 is an equidigital number, since it uses as much as digits as its factorization.

6661116097021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 46.

The spelling of 6661116097021 in words is "six trillion, six hundred sixty-one billion, one hundred sixteen million, ninety-seven thousand, twenty-one".