28666457 has 4 divisors (see below), whose sum is σ = 29011920. Its totient is φ = 28320996.

The previous prime is 28666433. The next prime is 28666489. The reversal of 28666457 is 75466682.

28666457 is nontrivially palindromic in base 15.

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 28666457 - 2⁸ = 28666201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28666357) 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, 172607 + ... + 172772.

It is an arithmetic number, because the mean of its divisors is an integer number (7252980).

Almost surely, 2^28666457 is an apocalyptic number.

It is an amenable number.

28666457 is a deficient number, since it is larger than the sum of its proper divisors (345463).

28666457 is an equidigital number, since it uses as much as digits as its factorization.

28666457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345462.

The product of its digits is 483840, while the sum is 44.

The square root of 28666457 is about 5354.1065547858. The cubic root of 28666457 is about 306.0492644279.

The spelling of 28666457 in words is "twenty-eight million, six hundred sixty-six thousand, four hundred fifty-seven".