28208644 has 12 divisors (see below), whose sum is σ = 52269084. Its totient is φ = 13274624.

The previous prime is 28208641. The next prime is 28208681. The reversal of 28208644 is 44680282.

It can be written as a sum of positive squares in 2 ways, for example, as 22448644 + 5760000 = 4738^2 + 2400^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (28208641) 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, 207349 + ... + 207484.

It is an arithmetic number, because the mean of its divisors is an integer number (4355757).

Almost surely, 2^28208644 is an apocalyptic number.

It is an amenable number.

28208644 is a deficient number, since it is larger than the sum of its proper divisors (24060440).

28208644 is a wasteful number, since it uses less digits than its factorization.

28208644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414854 (or 414852 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 34.

The square root of 28208644 is about 5311.1810362668. The cubic root of 28208644 is about 304.4112767880.

The spelling of 28208644 in words is "twenty-eight million, two hundred eight thousand, six hundred forty-four".