28515439 has 8 divisors (see below), whose sum is σ = 29691360. Its totient is φ = 27352416.

The previous prime is 28515427. The next prime is 28515449. The reversal of 28515439 is 93451582.

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 28515439 - 2¹³ = 28507247 is a prime.

It is a super-2 number, since 2×28515439² = 1626260522725442, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28515398 and 28515407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28515449) 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, 1422 + ... + 7684.

It is an arithmetic number, because the mean of its divisors is an integer number (3711420).

Almost surely, 2^28515439 is an apocalyptic number.

28515439 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

28515439 is a deficient number, since it is larger than the sum of its proper divisors (1175921).

28515439 is a wasteful number, since it uses less digits than its factorization.

28515439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6449.

The product of its digits is 43200, while the sum is 37.

The square root of 28515439 is about 5339.9849250724. The cubic root of 28515439 is about 305.5108843468.

The spelling of 28515439 in words is "twenty-eight million, five hundred fifteen thousand, four hundred thirty-nine".