28628878 has 8 divisors (see below), whose sum is σ = 42997968. Its totient is φ = 14296224.

The previous prime is 28628843. The next prime is 28628891. The reversal of 28628878 is 87882682.

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

It is a super-2 number, since 2×28628878² = 1639225311077768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7051 + ... + 10342.

It is an arithmetic number, because the mean of its divisors is an integer number (5374746).

Almost surely, 2^28628878 is an apocalyptic number.

28628878 is a deficient number, since it is larger than the sum of its proper divisors (14369090).

28628878 is a wasteful number, since it uses less digits than its factorization.

28628878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18218.

The product of its digits is 688128, while the sum is 49.

The square root of 28628878 is about 5350.5960415640. The cubic root of 28628878 is about 305.9154721173.

The spelling of 28628878 in words is "twenty-eight million, six hundred twenty-eight thousand, eight hundred seventy-eight".