28017972 has 54 divisors (see below), whose sum is σ = 75262278. Its totient is φ = 8786688.

The previous prime is 28017967. The next prime is 28018009. The reversal of 28017972 is 27971082.

It can be written as a sum of positive squares in 3 ways, for example, as 10074276 + 17943696 = 3174^2 + 4236^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 9058 + ... + 11750.

Almost surely, 2^28017972 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28017972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37631139).

28017972 is an abundant number, since it is smaller than the sum of its proper divisors (47244306).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28017972 is a wasteful number, since it uses less digits than its factorization.

28017972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2737 (or 2715 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 28017972 is about 5293.2005440943. The cubic root of 28017972 is about 303.7238518364.

The spelling of 28017972 in words is "twenty-eight million, seventeen thousand, nine hundred seventy-two".