77797409 has 2 divisors, whose sum is σ = 77797410. Its totient is φ = 77797408.

The previous prime is 77797403. The next prime is 77797411. The reversal of 77797409 is 90479777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44849809 + 32947600 = 6697^2 + 5740^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77797409 is a prime.

It is a super-2 number, since 2×77797409² = 12104873694226562, which contains 22 as substring.

Together with 77797411, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77797403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38898704 + 38898705.

It is an arithmetic number, because the mean of its divisors is an integer number (38898705).

Almost surely, 2^77797409 is an apocalyptic number.

It is an amenable number.

77797409 is a deficient number, since it is larger than the sum of its proper divisors (1).

77797409 is an equidigital number, since it uses as much as digits as its factorization.

77797409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 777924, while the sum is 50.

The square root of 77797409 is about 8820.2839523453. The cubic root of 77797409 is about 426.8956319759.

The spelling of 77797409 in words is "seventy-seven million, seven hundred ninety-seven thousand, four hundred nine".