28501257 has 4 divisors (see below), whose sum is σ = 38001680. Its totient is φ = 19000836.

The previous prime is 28501241. The next prime is 28501327. The reversal of 28501257 is 75210582.

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 not a de Polignac number, because 28501257 - 2⁴ = 28501241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28501237) 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, 4750207 + ... + 4750212.

It is an arithmetic number, because the mean of its divisors is an integer number (9500420).

Almost surely, 2^28501257 is an apocalyptic number.

It is an amenable number.

28501257 is a deficient number, since it is larger than the sum of its proper divisors (9500423).

28501257 is an equidigital number, since it uses as much as digits as its factorization.

28501257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9500422.

The product of its (nonzero) digits is 5600, while the sum is 30.

The square root of 28501257 is about 5338.6568535541. The cubic root of 28501257 is about 305.4602278837.

The spelling of 28501257 in words is "twenty-eight million, five hundred one thousand, two hundred fifty-seven".