28171636 has 12 divisors (see below), whose sum is σ = 49420420. Its totient is φ = 14051520.

The previous prime is 28171621. The next prime is 28171639. The reversal of 28171636 is 63617182.

It can be written as a sum of positive squares in 2 ways, for example, as 6604900 + 21566736 = 2570^2 + 4644^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28171639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6681 + ... + 10048.

Almost surely, 2^28171636 is an apocalyptic number.

It is an amenable number.

28171636 is a deficient number, since it is larger than the sum of its proper divisors (21248784).

28171636 is a wasteful number, since it uses less digits than its factorization.

28171636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17154 (or 17152 counting only the distinct ones).

The product of its digits is 12096, while the sum is 34.

The square root of 28171636 is about 5307.6959219609. The cubic root of 28171636 is about 304.2780955931.

It can be divided in two parts, 281 and 71636, that added together give a palindrome (71917).

The spelling of 28171636 in words is "twenty-eight million, one hundred seventy-one thousand, six hundred thirty-six".