77211109 has 2 divisors, whose sum is σ = 77211110. Its totient is φ = 77211108.

The previous prime is 77211097. The next prime is 77211139. The reversal of 77211109 is 90111277.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73582084 + 3629025 = 8578^2 + 1905^2 .

It is an emirp because it is prime and its reverse (90111277) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77211109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77211139) 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, 38605554 + 38605555.

It is an arithmetic number, because the mean of its divisors is an integer number (38605555).

Almost surely, 2^77211109 is an apocalyptic number.

It is an amenable number.

77211109 is a deficient number, since it is larger than the sum of its proper divisors (1).

77211109 is an equidigital number, since it uses as much as digits as its factorization.

77211109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 882, while the sum is 28.

The square root of 77211109 is about 8786.9852054046. The cubic root of 77211109 is about 425.8205306163.

It can be divided in two parts, 772 and 11109, that added together give a square (11881 = 109²).

The spelling of 77211109 in words is "seventy-seven million, two hundred eleven thousand, one hundred nine".