28297997825 has 6 divisors (see below), whose sum is σ = 35089517334. Its totient is φ = 22638398240.

The previous prime is 28297997821. The next prime is 28297997851. The reversal of 28297997825 is 52879979282.

It can be written as a sum of positive squares in 3 ways, for example, as 1564439809 + 26733558016 = 39553^2 + 163504^2 .

It is not a de Polignac number, because 28297997825 - 2² = 28297997821 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28297997821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 565959932 + ... + 565959981.

It is an arithmetic number, because the mean of its divisors is an integer number (5848252889).

Almost surely, 2^28297997825 is an apocalyptic number.

28297997825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28297997825 is a deficient number, since it is larger than the sum of its proper divisors (6791519509).

28297997825 is a wasteful number, since it uses less digits than its factorization.

28297997825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1131919923 (or 1131919918 counting only the distinct ones).

The product of its digits is 91445760, while the sum is 68.

The spelling of 28297997825 in words is "twenty-eight billion, two hundred ninety-seven million, nine hundred ninety-seven thousand, eight hundred twenty-five".