28120491 has 24 divisors (see below), whose sum is σ = 46675200. Its totient is φ = 15980976.

The previous prime is 28120487. The next prime is 28120511. The reversal of 28120491 is 19402182.

It is not a de Polignac number, because 28120491 - 2² = 28120487 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28120471) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11416 + ... + 13658.

It is an arithmetic number, because the mean of its divisors is an integer number (1944800).

Almost surely, 2^28120491 is an apocalyptic number.

28120491 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28120491 is a deficient number, since it is larger than the sum of its proper divisors (18554709).

28120491 is a wasteful number, since it uses less digits than its factorization.

28120491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2455 (or 2452 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 28120491 is about 5302.8757292624. The cubic root of 28120491 is about 304.0938472664.

The spelling of 28120491 in words is "twenty-eight million, one hundred twenty thousand, four hundred ninety-one".