28646388 has 36 divisors (see below), whose sum is σ = 73644480. Its totient is φ = 9386256.

The previous prime is 28646383. The next prime is 28646389. The reversal of 28646388 is 88364682.

It is a happy number.

28646388 is a `hidden beast` number, since 2 + 8 + 6 + 4 + 638 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28646381) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4620 + ... + 8867.

It is an arithmetic number, because the mean of its divisors is an integer number (2045680).

Almost surely, 2^28646388 is an apocalyptic number.

It is an amenable number.

28646388 is an abundant number, since it is smaller than the sum of its proper divisors (44998092).

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

28646388 is a wasteful number, since it uses less digits than its factorization.

28646388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13556 (or 13551 counting only the distinct ones).

The product of its digits is 442368, while the sum is 45.

The square root of 28646388 is about 5352.2320577494. The cubic root of 28646388 is about 305.9778274335.

It can be divided in two parts, 28 and 646388, that added together give a square (646416 = 804²).

The spelling of 28646388 in words is "twenty-eight million, six hundred forty-six thousand, three hundred eighty-eight".