7779881 has 2 divisors, whose sum is σ = 7779882. Its totient is φ = 7779880.

The previous prime is 7779869. The next prime is 7779883. The reversal of 7779881 is 1889777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7376656 + 403225 = 2716^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 7779881 - 2¹⁸ = 7517737 is a prime.

It is a super-2 number, since 2×7779881² = 121053096748322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 7779883, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (7779883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3889940 + 3889941.

It is an arithmetic number, because the mean of its divisors is an integer number (3889941).

Almost surely, 2^7779881 is an apocalyptic number.

It is an amenable number.

7779881 is a deficient number, since it is larger than the sum of its proper divisors (1).

7779881 is an equidigital number, since it uses as much as digits as its factorization.

7779881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 197568, while the sum is 47.

The square root of 7779881 is about 2789.2438043312. The cubic root of 7779881 is about 198.1485892760.

The spelling of 7779881 in words is "seven million, seven hundred seventy-nine thousand, eight hundred eighty-one".