28785451 has 4 divisors (see below), whose sum is σ = 29273400. Its totient is φ = 28297504.

The previous prime is 28785409. The next prime is 28785457. The reversal of 28785451 is 15458782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15458782 = 2 ⋅7729391.

It is a cyclic number.

It is not a de Polignac number, because 28785451 - 2⁹ = 28784939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28785457) 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, 243886 + ... + 244003.

It is an arithmetic number, because the mean of its divisors is an integer number (7318350).

Almost surely, 2^28785451 is an apocalyptic number.

28785451 is a deficient number, since it is larger than the sum of its proper divisors (487949).

28785451 is an equidigital number, since it uses as much as digits as its factorization.

28785451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487948.

The product of its digits is 89600, while the sum is 40.

The square root of 28785451 is about 5365.2074517208. The cubic root of 28785451 is about 306.4721483562.

The spelling of 28785451 in words is "twenty-eight million, seven hundred eighty-five thousand, four hundred fifty-one".