28564278 has 8 divisors (see below), whose sum is σ = 57128568. Its totient is φ = 9521424.

The previous prime is 28564273. The next prime is 28564279. The reversal of 28564278 is 87246582.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

28564278 is an admirable number.

It is a super-2 number, since 2×28564278² = 1631835955322568, which contains 22 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 (28564271) 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, 2380351 + ... + 2380362.

It is an arithmetic number, because the mean of its divisors is an integer number (7141071).

Almost surely, 2^28564278 is an apocalyptic number.

28564278 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28564278 is a wasteful number, since it uses less digits than its factorization.

28564278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4760718.

The product of its digits is 215040, while the sum is 42.

The square root of 28564278 is about 5344.5559216833. Note that the first 3 decimals coincide. The cubic root of 28564278 is about 305.6852031986.

The spelling of 28564278 in words is "twenty-eight million, five hundred sixty-four thousand, two hundred seventy-eight".