28911905 has 8 divisors (see below), whose sum is σ = 37848384. Its totient is φ = 21026800.

The previous prime is 28911899. The next prime is 28911919. The reversal of 28911905 is 50911982.

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

It is not a de Polignac number, because 28911905 - 2⁴ = 28911889 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 262781 + ... + 262890.

It is an arithmetic number, because the mean of its divisors is an integer number (4731048).

Almost surely, 2^28911905 is an apocalyptic number.

It is an amenable number.

28911905 is a deficient number, since it is larger than the sum of its proper divisors (8936479).

28911905 is a wasteful number, since it uses less digits than its factorization.

28911905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525687.

The product of its (nonzero) digits is 6480, while the sum is 35.

The square root of 28911905 is about 5376.9791705008. The cubic root of 28911905 is about 306.9202684577.

The spelling of 28911905 in words is "twenty-eight million, nine hundred eleven thousand, nine hundred five".