28022501 has 8 divisors (see below), whose sum is σ = 30313080. Its totient is φ = 25751232.

The previous prime is 28022447. The next prime is 28022503. The reversal of 28022501 is 10522082.

It can be written as a sum of positive squares in 4 ways, for example, as 15249025 + 12773476 = 3905^2 + 3574^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-28022501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28022503) 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, 1730 + ... + 7683.

It is an arithmetic number, because the mean of its divisors is an integer number (3789135).

Almost surely, 2^28022501 is an apocalyptic number.

It is an amenable number.

28022501 is a deficient number, since it is larger than the sum of its proper divisors (2290579).

28022501 is a wasteful number, since it uses less digits than its factorization.

28022501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9655.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 28022501 is about 5293.6283398063. The cubic root of 28022501 is about 303.7402162282.

Adding to 28022501 its reverse (10522082), we get a palindrome (38544583).

The spelling of 28022501 in words is "twenty-eight million, twenty-two thousand, five hundred one".