2666616391 has 2 divisors, whose sum is σ = 2666616392. Its totient is φ = 2666616390.

The previous prime is 2666616289. The next prime is 2666616397. The reversal of 2666616391 is 1936166662.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2666616391 - 2⁷ = 2666616263 is a prime.

It is a super-2 number, since 2×2666616391² = 14221685953499729762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2666616397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1333308195 + 1333308196.

It is an arithmetic number, because the mean of its divisors is an integer number (1333308196).

Almost surely, 2^2666616391 is an apocalyptic number.

2666616391 is a deficient number, since it is larger than the sum of its proper divisors (1).

2666616391 is an equidigital number, since it uses as much as digits as its factorization.

2666616391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 419904, while the sum is 46.

The square root of 2666616391 is about 51639.2911550885. The cubic root of 2666616391 is about 1386.7138338464.

The spelling of 2666616391 in words is "two billion, six hundred sixty-six million, six hundred sixteen thousand, three hundred ninety-one".