28378417 has 4 divisors (see below), whose sum is σ = 28671076. Its totient is φ = 28085760.

The previous prime is 28378411. The next prime is 28378421. The reversal of 28378417 is 71487382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71487382 = 2 ⋅35743691.

It can be written as a sum of positive squares in 2 ways, for example, as 22429696 + 5948721 = 4736^2 + 2439^2 .

It is a cyclic number.

It is not a de Polignac number, because 28378417 - 2⁷ = 28378289 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28378417.

It is not an unprimeable number, because it can be changed into a prime (28378411) 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, 146184 + ... + 146377.

It is an arithmetic number, because the mean of its divisors is an integer number (7167769).

Almost surely, 2^28378417 is an apocalyptic number.

It is an amenable number.

28378417 is a deficient number, since it is larger than the sum of its proper divisors (292659).

28378417 is an equidigital number, since it uses as much as digits as its factorization.

28378417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292658.

The product of its digits is 75264, while the sum is 40.

The square root of 28378417 is about 5327.1396640223. The cubic root of 28378417 is about 305.0207528654.

The spelling of 28378417 in words is "twenty-eight million, three hundred seventy-eight thousand, four hundred seventeen".