28381915 has 8 divisors (see below), whose sum is σ = 35850960. Its totient is φ = 21510432.

The previous prime is 28381907. The next prime is 28381919. The reversal of 28381915 is 51918382.

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

It is not a de Polignac number, because 28381915 - 2³ = 28381907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28381919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149284 + ... + 149473.

It is an arithmetic number, because the mean of its divisors is an integer number (4481370).

Almost surely, 2^28381915 is an apocalyptic number.

28381915 is a deficient number, since it is larger than the sum of its proper divisors (7469045).

28381915 is a wasteful number, since it uses less digits than its factorization.

28381915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298781.

The product of its digits is 17280, while the sum is 37.

The square root of 28381915 is about 5327.4679726865. The cubic root of 28381915 is about 305.0332849100.

It can be divided in two parts, 2838 and 1915, that added together give a triangular number (4753 = T₉₇).

The spelling of 28381915 in words is "twenty-eight million, three hundred eighty-one thousand, nine hundred fifteen".