28257999449 has 4 divisors (see below), whose sum is σ = 28258414464. Its totient is φ = 28257584436.

The previous prime is 28257999443. The next prime is 28257999463. The reversal of 28257999449 is 94499975282.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28257999449 - 2²⁰ = 28256950873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28257999443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78737 + ... + 250430.

It is an arithmetic number, because the mean of its divisors is an integer number (7064603616).

Almost surely, 2^28257999449 is an apocalyptic number.

It is an amenable number.

28257999449 is a deficient number, since it is larger than the sum of its proper divisors (415015).

28257999449 is an equidigital number, since it uses as much as digits as its factorization.

28257999449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415014.

The product of its digits is 117573120, while the sum is 68.

The spelling of 28257999449 in words is "twenty-eight billion, two hundred fifty-seven million, nine hundred ninety-nine thousand, four hundred forty-nine".