28320775425 has 18 divisors (see below), whose sum is σ = 50725655942. Its totient is φ = 15104413440.

The previous prime is 28320775421. The next prime is 28320775433. The reversal of 28320775425 is 52457702382.

28320775425 is a `hidden beast` number, since 2 + 8 + 32 + 0 + 77 + 542 + 5 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 7908367041 + 20412408384 = 88929^2 + 142872^2 .

It is not a de Polignac number, because 28320775425 - 2² = 28320775421 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28320775421) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 62934832 + ... + 62935281.

Almost surely, 2^28320775425 is an apocalyptic number.

28320775425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28320775425 is a deficient number, since it is larger than the sum of its proper divisors (22404880517).

28320775425 is a wasteful number, since it uses less digits than its factorization.

28320775425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125870129 (or 125870121 counting only the distinct ones).

The product of its (nonzero) digits is 940800, while the sum is 45.

The spelling of 28320775425 in words is "twenty-eight billion, three hundred twenty million, seven hundred seventy-five thousand, four hundred twenty-five".