28478639 has 8 divisors (see below), whose sum is σ = 32581248. Its totient is φ = 24384600.

The previous prime is 28478633. The next prime is 28478657. The reversal of 28478639 is 93687482.

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

It is a cyclic number.

It is not a de Polignac number, because 28478639 - 2²⁰ = 27430063 is a prime.

It is a super-2 number, since 2×28478639² = 1622065758584642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28478593 and 28478602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28478633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8564 + ... + 11414.

It is an arithmetic number, because the mean of its divisors is an integer number (4072656).

Almost surely, 2^28478639 is an apocalyptic number.

28478639 is a deficient number, since it is larger than the sum of its proper divisors (4102609).

28478639 is a wasteful number, since it uses less digits than its factorization.

28478639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4285.

The product of its digits is 580608, while the sum is 47.

The square root of 28478639 is about 5336.5381100485. The cubic root of 28478639 is about 305.3794042224.

The spelling of 28478639 in words is "twenty-eight million, four hundred seventy-eight thousand, six hundred thirty-nine".