77542813 has 2 divisors, whose sum is σ = 77542814. Its totient is φ = 77542812.

The previous prime is 77542807. The next prime is 77542837. The reversal of 77542813 is 31824577.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61042969 + 16499844 = 7813^2 + 4062^2 .

It is a cyclic number.

It is not a de Polignac number, because 77542813 - 2⁹ = 77542301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77542853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38771406 + 38771407.

It is an arithmetic number, because the mean of its divisors is an integer number (38771407).

Almost surely, 2^77542813 is an apocalyptic number.

It is an amenable number.

77542813 is a deficient number, since it is larger than the sum of its proper divisors (1).

77542813 is an equidigital number, since it uses as much as digits as its factorization.

77542813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 47040, while the sum is 37.

The square root of 77542813 is about 8805.8397101015. The cubic root of 77542813 is about 426.4294438007.

The spelling of 77542813 in words is "seventy-seven million, five hundred forty-two thousand, eight hundred thirteen".