77138791 has 2 divisors, whose sum is σ = 77138792. Its totient is φ = 77138790.

The previous prime is 77138777. The next prime is 77138827. The reversal of 77138791 is 19783177.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77138791 - 2⁵ = 77138759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77138701) 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, 38569395 + 38569396.

It is an arithmetic number, because the mean of its divisors is an integer number (38569396).

Almost surely, 2^77138791 is an apocalyptic number.

77138791 is a deficient number, since it is larger than the sum of its proper divisors (1).

77138791 is an equidigital number, since it uses as much as digits as its factorization.

77138791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 74088, while the sum is 43.

The square root of 77138791 is about 8782.8691781217. The cubic root of 77138791 is about 425.6875441032.

The spelling of 77138791 in words is "seventy-seven million, one hundred thirty-eight thousand, seven hundred ninety-one".