28457645 has 4 divisors (see below), whose sum is σ = 34149180. Its totient is φ = 22766112.

The previous prime is 28457641. The next prime is 28457669. The reversal of 28457645 is 54675482.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54675482 = 2 ⋅27337741.

It can be written as a sum of positive squares in 2 ways, for example, as 3247204 + 25210441 = 1802^2 + 5021^2 .

It is a cyclic number.

It is not a de Polignac number, because 28457645 - 2² = 28457641 is a prime.

It is a super-3 number, since 3×28457645³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28457641) 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, 2845760 + ... + 2845769.

It is an arithmetic number, because the mean of its divisors is an integer number (8537295).

Almost surely, 2^28457645 is an apocalyptic number.

It is an amenable number.

28457645 is a deficient number, since it is larger than the sum of its proper divisors (5691535).

28457645 is an equidigital number, since it uses as much as digits as its factorization.

28457645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5691534.

The product of its digits is 268800, while the sum is 41.

The square root of 28457645 is about 5334.5707418686. The cubic root of 28457645 is about 305.3043454944.

The spelling of 28457645 in words is "twenty-eight million, four hundred fifty-seven thousand, six hundred forty-five".