28553638 has 4 divisors (see below), whose sum is σ = 42830460. Its totient is φ = 14276818.

The previous prime is 28553633. The next prime is 28553639. The reversal of 28553638 is 83635582.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 28553638.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28553633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7138408 + ... + 7138411.

It is an arithmetic number, because the mean of its divisors is an integer number (10707615).

Almost surely, 2^28553638 is an apocalyptic number.

28553638 is a deficient number, since it is larger than the sum of its proper divisors (14276822).

28553638 is a wasteful number, since it uses less digits than its factorization.

28553638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14276821.

The product of its digits is 172800, while the sum is 40.

The square root of 28553638 is about 5343.5604235378. The cubic root of 28553638 is about 305.6472432627.

The spelling of 28553638 in words is "twenty-eight million, five hundred fifty-three thousand, six hundred thirty-eight".