77211691 has 2 divisors, whose sum is σ = 77211692. Its totient is φ = 77211690.

The previous prime is 77211689. The next prime is 77211697. The reversal of 77211691 is 19611277.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77211691 - 2¹ = 77211689 is a prime.

Together with 77211689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (77211697) 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, 38605845 + 38605846.

It is an arithmetic number, because the mean of its divisors is an integer number (38605846).

Almost surely, 2^77211691 is an apocalyptic number.

77211691 is a deficient number, since it is larger than the sum of its proper divisors (1).

77211691 is an equidigital number, since it uses as much as digits as its factorization.

77211691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5292, while the sum is 34.

The square root of 77211691 is about 8787.0183225028. The cubic root of 77211691 is about 425.8216005267.

The spelling of 77211691 in words is "seventy-seven million, two hundred eleven thousand, six hundred ninety-one".