28730331 has 12 divisors (see below), whose sum is σ = 47427952. Its totient is φ = 16417296.

The previous prime is 28730297. The next prime is 28730341. The reversal of 28730331 is 13303782.

It is not a de Polignac number, because 28730331 - 2⁶ = 28730267 is a prime.

It is a super-2 number, since 2×28730331² = 1650863838739122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28730295 and 28730304.

It is not an unprimeable number, because it can be changed into a prime (28730341) 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, 227956 + ... + 228081.

Almost surely, 2^28730331 is an apocalyptic number.

28730331 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28730331 is a deficient number, since it is larger than the sum of its proper divisors (18697621).

28730331 is a wasteful number, since it uses less digits than its factorization.

28730331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456050 (or 456047 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 28730331 is about 5360.0681898648. The cubic root of 28730331 is about 306.2764066637.

The spelling of 28730331 in words is "twenty-eight million, seven hundred thirty thousand, three hundred thirty-one".