28375644 has 24 divisors (see below), whose sum is σ = 72229248. Its totient is φ = 8598640.

The previous prime is 28375631. The next prime is 28375663. The reversal of 28375644 is 44657382.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107352 + ... + 107615.

It is an arithmetic number, because the mean of its divisors is an integer number (3009552).

Almost surely, 2^28375644 is an apocalyptic number.

It is an amenable number.

28375644 is an abundant number, since it is smaller than the sum of its proper divisors (43853604).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28375644 is a wasteful number, since it uses less digits than its factorization.

28375644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214985 (or 214983 counting only the distinct ones).

The product of its digits is 161280, while the sum is 39.

The square root of 28375644 is about 5326.8793866578. The cubic root of 28375644 is about 305.0108174968.

The spelling of 28375644 in words is "twenty-eight million, three hundred seventy-five thousand, six hundred forty-four".