77121773 has 2 divisors, whose sum is σ = 77121774. Its totient is φ = 77121772.

The previous prime is 77121767. The next prime is 77121797. The reversal of 77121773 is 37712177.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76352644 + 769129 = 8738^2 + 877^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77121773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77121743) 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, 38560886 + 38560887.

It is an arithmetic number, because the mean of its divisors is an integer number (38560887).

Almost surely, 2^77121773 is an apocalyptic number.

It is an amenable number.

77121773 is a deficient number, since it is larger than the sum of its proper divisors (1).

77121773 is an equidigital number, since it uses as much as digits as its factorization.

77121773 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14406, while the sum is 35.

The square root of 77121773 is about 8781.9003068812. The cubic root of 77121773 is about 425.6562374012.

The spelling of 77121773 in words is "seventy-seven million, one hundred twenty-one thousand, seven hundred seventy-three".