28101901 has 8 divisors (see below), whose sum is σ = 29947320. Its totient is φ = 26277888.

The previous prime is 28101889. The next prime is 28101917. The reversal of 28101901 is 10910182.

It can be written as a sum of positive squares in 4 ways, for example, as 8970025 + 19131876 = 2995^2 + 4374^2 .

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 28101901 - 2¹¹ = 28099853 is a prime.

It is a super-3 number, since 3×28101901³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28101971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2596 + ... + 7933.

It is an arithmetic number, because the mean of its divisors is an integer number (3743415).

Almost surely, 2^28101901 is an apocalyptic number.

It is an amenable number.

28101901 is a deficient number, since it is larger than the sum of its proper divisors (1845419).

28101901 is a wasteful number, since it uses less digits than its factorization.

28101901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10703.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 28101901 is about 5301.1226169558. The cubic root of 28101901 is about 304.0268219928.

The spelling of 28101901 in words is "twenty-eight million, one hundred one thousand, nine hundred one".