28991255 has 8 divisors (see below), whose sum is σ = 35044272. Its totient is φ = 23023168.

The previous prime is 28991251. The next prime is 28991267. The reversal of 28991255 is 55219982.

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 28991255 - 2² = 28991251 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28991251) 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, 20477 + ... + 21846.

It is an arithmetic number, because the mean of its divisors is an integer number (4380534).

Almost surely, 2^28991255 is an apocalyptic number.

28991255 is a deficient number, since it is larger than the sum of its proper divisors (6053017).

28991255 is a wasteful number, since it uses less digits than its factorization.

28991255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42465.

The product of its digits is 64800, while the sum is 41.

The square root of 28991255 is about 5384.3527930476. The cubic root of 28991255 is about 307.2007973827.

The spelling of 28991255 in words is "twenty-eight million, nine hundred ninety-one thousand, two hundred fifty-five".