28457775491 has 2 divisors, whose sum is σ = 28457775492. Its totient is φ = 28457775490.

The previous prime is 28457775457. The next prime is 28457775497. The reversal of 28457775491 is 19457775482.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28457775491 - 2²² = 28453581187 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28457775491.

It is not a weakly prime, because it can be changed into another prime (28457775497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14228887745 + 14228887746.

It is an arithmetic number, because the mean of its divisors is an integer number (14228887746).

Almost surely, 2^28457775491 is an apocalyptic number.

28457775491 is a deficient number, since it is larger than the sum of its proper divisors (1).

28457775491 is an equidigital number, since it uses as much as digits as its factorization.

28457775491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19756800, while the sum is 59.

Subtracting from 28457775491 its reverse (19457775482), we obtain a palindrome (9000000009).

The spelling of 28457775491 in words is "twenty-eight billion, four hundred fifty-seven million, seven hundred seventy-five thousand, four hundred ninety-one".