28921580813 has 2 divisors, whose sum is σ = 28921580814. Its totient is φ = 28921580812.

The previous prime is 28921580749. The next prime is 28921580827. The reversal of 28921580813 is 31808512982.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28246516489 + 675064324 = 168067^2 + 25982^2 .

It is a cyclic number.

It is not a de Polignac number, because 28921580813 - 2⁶ = 28921580749 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 (28921520813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14460790406 + 14460790407.

It is an arithmetic number, because the mean of its divisors is an integer number (14460790407).

Almost surely, 2^28921580813 is an apocalyptic number.

It is an amenable number.

28921580813 is a deficient number, since it is larger than the sum of its proper divisors (1).

28921580813 is an equidigital number, since it uses as much as digits as its factorization.

28921580813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 276480, while the sum is 47.

The spelling of 28921580813 in words is "twenty-eight billion, nine hundred twenty-one million, five hundred eighty thousand, eight hundred thirteen".