28216986 has 48 divisors (see below), whose sum is σ = 65947584. Its totient is φ = 7884288.

The previous prime is 28216973. The next prime is 28217011. The reversal of 28216986 is 68961282.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 146106 + ... + 146298.

It is an arithmetic number, because the mean of its divisors is an integer number (1373908).

Almost surely, 2^28216986 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28216986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32973792).

28216986 is an abundant number, since it is smaller than the sum of its proper divisors (37730598).

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

28216986 is a wasteful number, since it uses less digits than its factorization.

28216986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 264 counting only the distinct ones).

The product of its digits is 82944, while the sum is 42.

The square root of 28216986 is about 5311.9663026040. The cubic root of 28216986 is about 304.4412811676.

The spelling of 28216986 in words is "twenty-eight million, two hundred sixteen thousand, nine hundred eighty-six".