28149409 has 2 divisors, whose sum is σ = 28149410. Its totient is φ = 28149408.

The previous prime is 28149397. The next prime is 28149419. The reversal of 28149409 is 90494182.

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., 18037009 + 10112400 = 4247^2 + 3180^2 .

It is a cyclic number.

It is not a de Polignac number, because 28149409 - 2⁷ = 28149281 is a prime.

It is not a weakly prime, because it can be changed into another prime (28149419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14074704 + 14074705.

It is an arithmetic number, because the mean of its divisors is an integer number (14074705).

Almost surely, 2^28149409 is an apocalyptic number.

It is an amenable number.

28149409 is a deficient number, since it is larger than the sum of its proper divisors (1).

28149409 is an equidigital number, since it uses as much as digits as its factorization.

28149409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 28149409 is about 5305.6016623942. The cubic root of 28149409 is about 304.1980509140.

The spelling of 28149409 in words is "twenty-eight million, one hundred forty-nine thousand, four hundred nine".