28981471 has 4 divisors (see below), whose sum is σ = 29764792. Its totient is φ = 28198152.

The previous prime is 28981457. The next prime is 28981487. The reversal of 28981471 is 17418982.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28981471 - 2⁵ = 28981439 is a prime.

It is a super-3 number, since 3×28981471³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28981571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 391605 + ... + 391678.

It is an arithmetic number, because the mean of its divisors is an integer number (7441198).

Almost surely, 2^28981471 is an apocalyptic number.

28981471 is a deficient number, since it is larger than the sum of its proper divisors (783321).

28981471 is an equidigital number, since it uses as much as digits as its factorization.

28981471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 783320.

The product of its digits is 32256, while the sum is 40.

The square root of 28981471 is about 5383.4441577860. Note that the first 3 decimals coincide. The cubic root of 28981471 is about 307.1662353423.

The spelling of 28981471 in words is "twenty-eight million, nine hundred eighty-one thousand, four hundred seventy-one".