2668437991 has 2 divisors, whose sum is σ = 2668437992. Its totient is φ = 2668437990.

The previous prime is 2668437979. The next prime is 2668438027. The reversal of 2668437991 is 1997348662.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2668437991 - 2²¹ = 2666340839 is a prime.

It is a super-2 number, since 2×2668437991² = 14241122623624232162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2668437911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1334218995 + 1334218996.

It is an arithmetic number, because the mean of its divisors is an integer number (1334218996).

Almost surely, 2^2668437991 is an apocalyptic number.

2668437991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2668437991 is an equidigital number, since it uses as much as digits as its factorization.

2668437991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3919104, while the sum is 55.

The square root of 2668437991 is about 51656.9258764011. The cubic root of 2668437991 is about 1387.0295226668.

The spelling of 2668437991 in words is "two billion, six hundred sixty-eight million, four hundred thirty-seven thousand, nine hundred ninety-one".