28561257 has 24 divisors (see below), whose sum is σ = 42162120. Its totient is φ = 18627840.

The previous prime is 28561249. The next prime is 28561271. The reversal of 28561257 is 75216582.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1218816 + 27342441 = 1104^2 + 5229^2 .

It is not a de Polignac number, because 28561257 - 2³ = 28561249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28561277) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 144883 + ... + 145079.

It is an arithmetic number, because the mean of its divisors is an integer number (1756755).

Almost surely, 2^28561257 is an apocalyptic number.

It is an amenable number.

28561257 is a deficient number, since it is larger than the sum of its proper divisors (13600863).

28561257 is a wasteful number, since it uses less digits than its factorization.

28561257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473 (or 470 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 28561257 is about 5344.2732901677. The cubic root of 28561257 is about 305.6744262467.

The spelling of 28561257 in words is "twenty-eight million, five hundred sixty-one thousand, two hundred fifty-seven".