28131449 has 2 divisors, whose sum is σ = 28131450. Its totient is φ = 28131448.

The previous prime is 28131409. The next prime is 28131473. The reversal of 28131449 is 94413182.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28015849 + 115600 = 5293^2 + 340^2 .

It is a cyclic number.

It is not a de Polignac number, because 28131449 - 2¹⁶ = 28065913 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28131409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14065724 + 14065725.

It is an arithmetic number, because the mean of its divisors is an integer number (14065725).

Almost surely, 2^28131449 is an apocalyptic number.

It is an amenable number.

28131449 is a deficient number, since it is larger than the sum of its proper divisors (1).

28131449 is an equidigital number, since it uses as much as digits as its factorization.

28131449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 32.

The square root of 28131449 is about 5303.9088415997. The cubic root of 28131449 is about 304.1333419257.

The spelling of 28131449 in words is "twenty-eight million, one hundred thirty-one thousand, four hundred forty-nine".