28431331 has 2 divisors, whose sum is σ = 28431332. Its totient is φ = 28431330.

The previous prime is 28431313. The next prime is 28431349. The reversal of 28431331 is 13313482.

Together with previous prime (28431313) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (28431313) and next prime (28431349).

It is a cyclic number.

It is not a de Polignac number, because 28431331 - 2¹³ = 28423139 is a prime.

It is a super-2 number, since 2×28431331² = 1616681164863122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28431296 and 28431305.

It is not a weakly prime, because it can be changed into another prime (28431031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14215665 + 14215666.

It is an arithmetic number, because the mean of its divisors is an integer number (14215666).

Almost surely, 2^28431331 is an apocalyptic number.

28431331 is a deficient number, since it is larger than the sum of its proper divisors (1).

28431331 is an equidigital number, since it uses as much as digits as its factorization.

28431331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 25.

The square root of 28431331 is about 5332.1038061913. The cubic root of 28431331 is about 305.2102143037.

The spelling of 28431331 in words is "twenty-eight million, four hundred thirty-one thousand, three hundred thirty-one".