77691457 has 2 divisors, whose sum is σ = 77691458. Its totient is φ = 77691456.

The previous prime is 77691451. The next prime is 77691461. The reversal of 77691457 is 75419677.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53129521 + 24561936 = 7289^2 + 4956^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77691457 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77691451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38845728 + 38845729.

It is an arithmetic number, because the mean of its divisors is an integer number (38845729).

Almost surely, 2^77691457 is an apocalyptic number.

It is an amenable number.

77691457 is a deficient number, since it is larger than the sum of its proper divisors (1).

77691457 is an equidigital number, since it uses as much as digits as its factorization.

77691457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 370440, while the sum is 46.

The square root of 77691457 is about 8814.2757501680. The cubic root of 77691457 is about 426.7017480785.

The spelling of 77691457 in words is "seventy-seven million, six hundred ninety-one thousand, four hundred fifty-seven".