28687478 has 4 divisors (see below), whose sum is σ = 43031220. Its totient is φ = 14343738.

The previous prime is 28687447. The next prime is 28687481. The reversal of 28687478 is 87478682.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87478682 = 2 ⋅43739341.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7171868 + ... + 7171871.

It is an arithmetic number, because the mean of its divisors is an integer number (10757805).

Almost surely, 2^28687478 is an apocalyptic number.

28687478 is a deficient number, since it is larger than the sum of its proper divisors (14343742).

28687478 is a wasteful number, since it uses less digits than its factorization.

28687478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14343741.

The product of its digits is 1204224, while the sum is 50.

The square root of 28687478 is about 5356.0692676626. The cubic root of 28687478 is about 306.1240543898.

The spelling of 28687478 in words is "twenty-eight million, six hundred eighty-seven thousand, four hundred seventy-eight".