28664394 has 48 divisors (see below), whose sum is σ = 65457504. Its totient is φ = 8298400.

The previous prime is 28664393. The next prime is 28664401. The reversal of 28664394 is 49346682.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (28664393) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34504 + ... + 35324.

It is an arithmetic number, because the mean of its divisors is an integer number (1363698).

Almost surely, 2^28664394 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28664394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32728752).

28664394 is an abundant number, since it is smaller than the sum of its proper divisors (36793110).

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

28664394 is a wasteful number, since it uses less digits than its factorization.

28664394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883 (or 860 counting only the distinct ones).

The product of its digits is 248832, while the sum is 42.

The square root of 28664394 is about 5353.9138954600. The cubic root of 28664394 is about 306.0419225744.

It can be divided in two parts, 2866 and 4394, that added together give a triangular number (7260 = T₁₂₀).

The spelling of 28664394 in words is "twenty-eight million, six hundred sixty-four thousand, three hundred ninety-four".