5120005216661 has 2 divisors, whose sum is σ = 5120005216662. Its totient is φ = 5120005216660.

The previous prime is 5120005216619. The next prime is 5120005216673. The reversal of 5120005216661 is 1666125000215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4058991913636 + 1061013303025 = 2014694^2 + 1030055^2 .

It is a cyclic number.

It is not a de Polignac number, because 5120005216661 - 2¹⁸ = 5120004954517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5120005219661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2560002608330 + 2560002608331.

It is an arithmetic number, because the mean of its divisors is an integer number (2560002608331).

Almost surely, 2^{5120005216661} is an apocalyptic number.

It is an amenable number.

5120005216661 is a deficient number, since it is larger than the sum of its proper divisors (1).

5120005216661 is an equidigital number, since it uses as much as digits as its factorization.

5120005216661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 35.

The spelling of 5120005216661 in words is "five trillion, one hundred twenty billion, five million, two hundred sixteen thousand, six hundred sixty-one".