77530813 has 2 divisors, whose sum is σ = 77530814. Its totient is φ = 77530812.

The previous prime is 77530801. The next prime is 77530819. The reversal of 77530813 is 31803577.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39917124 + 37613689 = 6318^2 + 6133^2 .

It is a cyclic number.

It is not a de Polignac number, because 77530813 - 2⁵ = 77530781 is a prime.

It is a super-3 number, since 3×77530813³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77530819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38765406 + 38765407.

It is an arithmetic number, because the mean of its divisors is an integer number (38765407).

Almost surely, 2^77530813 is an apocalyptic number.

It is an amenable number.

77530813 is a deficient number, since it is larger than the sum of its proper divisors (1).

77530813 is an equidigital number, since it uses as much as digits as its factorization.

77530813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 77530813 is about 8805.1583177135. The cubic root of 77530813 is about 426.4074455560.

The spelling of 77530813 in words is "seventy-seven million, five hundred thirty thousand, eight hundred thirteen".