28751481 has 12 divisors (see below), whose sum is σ = 45305520. Its totient is φ = 17425080.

The previous prime is 28751453. The next prime is 28751483. The reversal of 28751481 is 18415782.

It is not a de Polignac number, because 28751481 - 2⁶ = 28751417 is a prime.

It is a super-2 number, since 2×28751481² = 1653295319386722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28751483) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 145111 + ... + 145308.

It is an arithmetic number, because the mean of its divisors is an integer number (3775460).

Almost surely, 2^28751481 is an apocalyptic number.

It is an amenable number.

28751481 is a deficient number, since it is larger than the sum of its proper divisors (16554039).

28751481 is a wasteful number, since it uses less digits than its factorization.

28751481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290436 (or 290433 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 28751481 is about 5362.0407495654. The cubic root of 28751481 is about 306.3515439476.

It can be divided in two parts, 2875 and 1481, that added together give a square (4356 = 66²).

The spelling of 28751481 in words is "twenty-eight million, seven hundred fifty-one thousand, four hundred eighty-one".