28791457 has 6 divisors (see below), whose sum is σ = 28969874. Its totient is φ = 28614000.

The previous prime is 28791449. The next prime is 28791463. The reversal of 28791457 is 75419782.

It can be written as a sum of positive squares in only one way, i.e., 27783441 + 1008016 = 5271^2 + 1004^2 .

It is not a de Polignac number, because 28791457 - 2³ = 28791449 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28791407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 62773 + ... + 63229.

Almost surely, 2^28791457 is an apocalyptic number.

It is an amenable number.

28791457 is a deficient number, since it is larger than the sum of its proper divisors (178417).

28791457 is an frugal number, since it uses more digits than its factorization.

28791457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 959 (or 708 counting only the distinct ones).

The product of its digits is 141120, while the sum is 43.

The square root of 28791457 is about 5365.7671399344. The cubic root of 28791457 is about 306.4934617125.

The spelling of 28791457 in words is "twenty-eight million, seven hundred ninety-one thousand, four hundred fifty-seven".