28251939 has 8 divisors (see below), whose sum is σ = 37798992. Its totient is φ = 18769760.

The previous prime is 28251907. The next prime is 28251953. The reversal of 28251939 is 93915282.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28251939 - 2⁵ = 28251907 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28251897 and 28251906.

It is not an unprimeable number, because it can be changed into a prime (28256939) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15192 + ... + 16949.

It is an arithmetic number, because the mean of its divisors is an integer number (4724874).

Almost surely, 2^28251939 is an apocalyptic number.

28251939 is a deficient number, since it is larger than the sum of its proper divisors (9547053).

28251939 is a wasteful number, since it uses less digits than its factorization.

28251939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32437.

The product of its digits is 38880, while the sum is 39.

The square root of 28251939 is about 5315.2553090139. The cubic root of 28251939 is about 304.5669353311.

The spelling of 28251939 in words is "twenty-eight million, two hundred fifty-one thousand, nine hundred thirty-nine".