28809915 has 32 divisors (see below), whose sum is σ = 48591360. Its totient is φ = 14547456.

The previous prime is 28809901. The next prime is 28809929. The reversal of 28809915 is 51990882.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28809901) and next prime (28809929).

It is not a de Polignac number, because 28809915 - 2¹⁶ = 28744379 is a prime.

It is a super-2 number, since 2×28809915² = 1660022404614450, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38616 + ... + 39354.

It is an arithmetic number, because the mean of its divisors is an integer number (1518480).

Almost surely, 2^28809915 is an apocalyptic number.

28809915 is a deficient number, since it is larger than the sum of its proper divisors (19781445).

28809915 is a wasteful number, since it uses less digits than its factorization.

28809915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 883.

The product of its (nonzero) digits is 51840, while the sum is 42.

The square root of 28809915 is about 5367.4868420891. The cubic root of 28809915 is about 306.5589446531.

The spelling of 28809915 in words is "twenty-eight million, eight hundred nine thousand, nine hundred fifteen".