77028509 has 2 divisors, whose sum is σ = 77028510. Its totient is φ = 77028508.

The previous prime is 77028499. The next prime is 77028599. The reversal of 77028509 is 90582077.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65448100 + 11580409 = 8090^2 + 3403^2 .

It is an emirp because it is prime and its reverse (90582077) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77028509 - 2¹² = 77024413 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77028599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38514254 + 38514255.

It is an arithmetic number, because the mean of its divisors is an integer number (38514255).

Almost surely, 2^77028509 is an apocalyptic number.

It is an amenable number.

77028509 is a deficient number, since it is larger than the sum of its proper divisors (1).

77028509 is an equidigital number, since it uses as much as digits as its factorization.

77028509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35280, while the sum is 38.

The square root of 77028509 is about 8776.5886880952. The cubic root of 77028509 is about 425.4845849825.

The spelling of 77028509 in words is "seventy-seven million, twenty-eight thousand, five hundred nine".