28171897 has 8 divisors (see below), whose sum is σ = 30380616. Its totient is φ = 25969152.

The previous prime is 28171883. The next prime is 28171903. The reversal of 28171897 is 79817182.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 8271376 + 19900521 = 2876^2 + 4461^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28171897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28171817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15753 + ... + 17449.

It is an arithmetic number, because the mean of its divisors is an integer number (3797577).

Almost surely, 2^28171897 is an apocalyptic number.

It is an amenable number.

28171897 is a deficient number, since it is larger than the sum of its proper divisors (2208719).

28171897 is a wasteful number, since it uses less digits than its factorization.

28171897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2987.

The product of its digits is 56448, while the sum is 43.

The square root of 28171897 is about 5307.7205088437. The cubic root of 28171897 is about 304.2790352657.

The spelling of 28171897 in words is "twenty-eight million, one hundred seventy-one thousand, eight hundred ninety-seven".