28125637849 has 9 divisors (see below), whose sum is σ = 29133968383. Its totient is φ = 27151092472.

The previous prime is 28125637819. The next prime is 28125637853. The reversal of 28125637849 is 94873652182.

The square root of 28125637849 is 167707.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 14748402249 + 13377235600 = 121443^2 + 115660^2 .

It is not a de Polignac number, because 28125637849 - 2²⁹ = 27588766937 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28125637849.

It is not an unprimeable number, because it can be changed into a prime (28125637819) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4860612 + ... + 4866394.

Almost surely, 2^28125637849 is an apocalyptic number.

28125637849 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

28125637849 is the 167707-th square number.

28125637849 is the 83854-th centered octagonal number.

It is an amenable number.

28125637849 is a deficient number, since it is larger than the sum of its proper divisors (1008330534).

28125637849 is an frugal number, since it uses more digits than its factorization.

28125637849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11624 (or 5812 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 55.

The spelling of 28125637849 in words is "twenty-eight billion, one hundred twenty-five million, six hundred thirty-seven thousand, eight hundred forty-nine".