28525644 has 108 divisors (see below), whose sum is σ = 85232784. Its totient is φ = 8019648.

The previous prime is 28525639. The next prime is 28525649. The reversal of 28525644 is 44652582.

It is a happy number.

28525644 is a `hidden beast` number, since 2 + 8 + 5 + 2 + 5 + 644 = 666.

It is an interprime number because it is at equal distance from previous prime (28525639) and next prime (28525649).

It is a super-2 number, since 2×28525644² = 1627424731229472, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 28525599 and 28525608.

It is not an unprimeable number, because it can be changed into a prime (28525649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 181614 + ... + 181770.

Almost surely, 2^28525644 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 28525644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42616392).

28525644 is an abundant number, since it is smaller than the sum of its proper divisors (56707140).

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

28525644 is a wasteful number, since it uses less digits than its factorization.

28525644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284 (or 272 counting only the distinct ones).

The product of its digits is 76800, while the sum is 36.

The square root of 28525644 is about 5340.9403666396. The cubic root of 28525644 is about 305.5473250357.

The spelling of 28525644 in words is "twenty-eight million, five hundred twenty-five thousand, six hundred forty-four".