77605813 has 2 divisors, whose sum is σ = 77605814. Its totient is φ = 77605812.

The previous prime is 77605811. The next prime is 77605819. The reversal of 77605813 is 31850677.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50794129 + 26811684 = 7127^2 + 5178^2 .

It is a cyclic number.

It is not a de Polignac number, because 77605813 - 2¹ = 77605811 is a prime.

It is a super-2 number, since 2×77605813² = 12045324422781938, which contains 22 as substring.

Together with 77605811, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77605811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38802906 + 38802907.

It is an arithmetic number, because the mean of its divisors is an integer number (38802907).

Almost surely, 2^77605813 is an apocalyptic number.

It is an amenable number.

77605813 is a deficient number, since it is larger than the sum of its proper divisors (1).

77605813 is an equidigital number, since it uses as much as digits as its factorization.

77605813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 35280, while the sum is 37.

The square root of 77605813 is about 8809.4161554555. The cubic root of 77605813 is about 426.5448973661.

The spelling of 77605813 in words is "seventy-seven million, six hundred five thousand, eight hundred thirteen".