28713321 has 24 divisors (see below), whose sum is σ = 51047360. Its totient is φ = 15145056.

The previous prime is 28713317. The next prime is 28713331. The reversal of 28713321 is 12331782.

It is not a de Polignac number, because 28713321 - 2² = 28713317 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28713301) 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, 16711 + ... + 18348.

Almost surely, 2^28713321 is an apocalyptic number.

28713321 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28713321 is a deficient number, since it is larger than the sum of its proper divisors (22334039).

28713321 is a wasteful number, since it uses less digits than its factorization.

28713321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35085 (or 35082 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 28713321 is about 5358.4812213910. The cubic root of 28713321 is about 306.2159503446.

The spelling of 28713321 in words is "twenty-eight million, seven hundred thirteen thousand, three hundred twenty-one".