28057742509 has 2 divisors, whose sum is σ = 28057742510. Its totient is φ = 28057742508.

The previous prime is 28057742443. The next prime is 28057742521. The reversal of 28057742509 is 90524775082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15538370409 + 12519372100 = 124653^2 + 111890^2 .

It is a cyclic number.

It is not a de Polignac number, because 28057742509 - 2⁷ = 28057742381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28057742569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14028871254 + 14028871255.

It is an arithmetic number, because the mean of its divisors is an integer number (14028871255).

Almost surely, 2^28057742509 is an apocalyptic number.

It is an amenable number.

28057742509 is a deficient number, since it is larger than the sum of its proper divisors (1).

28057742509 is an equidigital number, since it uses as much as digits as its factorization.

28057742509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1411200, while the sum is 49.

The spelling of 28057742509 in words is "twenty-eight billion, fifty-seven million, seven hundred forty-two thousand, five hundred nine".