28239481 has 8 divisors (see below), whose sum is σ = 29286144. Its totient is φ = 27201360.

The previous prime is 28239467. The next prime is 28239487. The reversal of 28239481 is 18493282.

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 28239481 - 2⁷ = 28239353 is a prime.

It is a super-2 number, since 2×28239481² = 1594936574298722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28239481.

It is not an unprimeable number, because it can be changed into a prime (28239487) 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, 5031 + ... + 9043.

It is an arithmetic number, because the mean of its divisors is an integer number (3660768).

Almost surely, 2^28239481 is an apocalyptic number.

It is an amenable number.

28239481 is a deficient number, since it is larger than the sum of its proper divisors (1046663).

28239481 is a wasteful number, since it uses less digits than its factorization.

28239481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4271.

The product of its digits is 27648, while the sum is 37.

The square root of 28239481 is about 5314.0832699535. The cubic root of 28239481 is about 304.5221613809.

The spelling of 28239481 in words is "twenty-eight million, two hundred thirty-nine thousand, four hundred eighty-one".