77455813 has 2 divisors, whose sum is σ = 77455814. Its totient is φ = 77455812.

The previous prime is 77455811. The next prime is 77455901. The reversal of 77455813 is 31855477.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71115489 + 6340324 = 8433^2 + 2518^2 .

It is an emirp because it is prime and its reverse (31855477) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77455813 - 2¹ = 77455811 is a prime.

Together with 77455811, 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 (77455811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38727906 + 38727907.

It is an arithmetic number, because the mean of its divisors is an integer number (38727907).

Almost surely, 2^77455813 is an apocalyptic number.

It is an amenable number.

77455813 is a deficient number, since it is larger than the sum of its proper divisors (1).

77455813 is an equidigital number, since it uses as much as digits as its factorization.

77455813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 117600, while the sum is 40.

The square root of 77455813 is about 8800.8984200478. The cubic root of 77455813 is about 426.2699050740.

The spelling of 77455813 in words is "seventy-seven million, four hundred fifty-five thousand, eight hundred thirteen".