77886881 has 2 divisors, whose sum is σ = 77886882. Its totient is φ = 77886880.

The previous prime is 77886869. The next prime is 77886883. The reversal of 77886881 is 18868877.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75968656 + 1918225 = 8716^2 + 1385^2 .

It is an emirp because it is prime and its reverse (18868877) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77886881 is a prime.

It is a super-2 number, since 2×77886881² = 12132732463816322, which contains 22 as substring.

Together with 77886883, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77886883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38943440 + 38943441.

It is an arithmetic number, because the mean of its divisors is an integer number (38943441).

Almost surely, 2^77886881 is an apocalyptic number.

It is an amenable number.

77886881 is a deficient number, since it is larger than the sum of its proper divisors (1).

77886881 is an equidigital number, since it uses as much as digits as its factorization.

77886881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1204224, while the sum is 53.

The square root of 77886881 is about 8825.3544404743. The cubic root of 77886881 is about 427.0592217129.

The spelling of 77886881 in words is "seventy-seven million, eight hundred eighty-six thousand, eight hundred eighty-one".