28639425 has 12 divisors (see below), whose sum is σ = 47350640. Its totient is φ = 15274320.

The previous prime is 28639417. The next prime is 28639487. The reversal of 28639425 is 52493682.

It is a happy number.

It is not a de Polignac number, because 28639425 - 2³ = 28639417 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 190855 + ... + 191004.

Almost surely, 2^28639425 is an apocalyptic number.

28639425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28639425 is a deficient number, since it is larger than the sum of its proper divisors (18711215).

28639425 is a wasteful number, since it uses less digits than its factorization.

28639425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381872 (or 381867 counting only the distinct ones).

The product of its digits is 103680, while the sum is 39.

The square root of 28639425 is about 5351.5815419369. The cubic root of 28639425 is about 305.9530343572.

The spelling of 28639425 in words is "twenty-eight million, six hundred thirty-nine thousand, four hundred twenty-five".