28991045 has 16 divisors (see below), whose sum is σ = 36080640. Its totient is φ = 22339200.

The previous prime is 28991041. The next prime is 28991071. The reversal of 28991045 is 54019982.

It is not a de Polignac number, because 28991045 - 2² = 28991041 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28991041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55385 + ... + 55905.

It is an arithmetic number, because the mean of its divisors is an integer number (2255040).

Almost surely, 2^28991045 is an apocalyptic number.

It is an amenable number.

28991045 is a deficient number, since it is larger than the sum of its proper divisors (7089595).

28991045 is a wasteful number, since it uses less digits than its factorization.

28991045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 916.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 28991045 is about 5384.3332920613. Note that the first 3 decimals coincide. The cubic root of 28991045 is about 307.2000556381.

The spelling of 28991045 in words is "twenty-eight million, nine hundred ninety-one thousand, forty-five".