28756407 has 4 divisors (see below), whose sum is σ = 38341880. Its totient is φ = 19170936.

The previous prime is 28756391. The next prime is 28756447. The reversal of 28756407 is 70465782.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28756407 - 2⁴ = 28756391 is a prime.

It is the 5363-rd Hogben number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28756447) by changing a digit.

It is a nontrivial repunit in base 5362.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4792732 + ... + 4792737.

It is an arithmetic number, because the mean of its divisors is an integer number (9585470).

Almost surely, 2^28756407 is an apocalyptic number.

28756407 is a deficient number, since it is larger than the sum of its proper divisors (9585473).

28756407 is an equidigital number, since it uses as much as digits as its factorization.

28756407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9585472.

The product of its (nonzero) digits is 94080, while the sum is 39.

The square root of 28756407 is about 5362.5000699301. The cubic root of 28756407 is about 306.3690387163.

The spelling of 28756407 in words is "twenty-eight million, seven hundred fifty-six thousand, four hundred seven".