28077509 has 2 divisors, whose sum is σ = 28077510. Its totient is φ = 28077508.

The previous prime is 28077493. The next prime is 28077521. The reversal of 28077509 is 90577082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26522500 + 1555009 = 5150^2 + 1247^2 .

It is a cyclic number.

It is not a de Polignac number, because 28077509 - 2⁴ = 28077493 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28077529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14038754 + 14038755.

It is an arithmetic number, because the mean of its divisors is an integer number (14038755).

Almost surely, 2^28077509 is an apocalyptic number.

It is an amenable number.

28077509 is a deficient number, since it is larger than the sum of its proper divisors (1).

28077509 is an equidigital number, since it uses as much as digits as its factorization.

28077509 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 38.

The square root of 28077509 is about 5298.8214727428. The cubic root of 28077509 is about 303.9388330595.

The spelling of 28077509 in words is "twenty-eight million, seventy-seven thousand, five hundred nine".