28639716 has 72 divisors (see below), whose sum is σ = 79289280. Its totient is φ = 8019648.

The previous prime is 28639711. The next prime is 28639729. The reversal of 28639716 is 61793682.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (28639711) 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 23 ways as a sum of consecutive naturals, for example, 30705 + ... + 31623.

It is an arithmetic number, because the mean of its divisors is an integer number (1101240).

Almost surely, 2^28639716 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 28639716, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39644640).

28639716 is an abundant number, since it is smaller than the sum of its proper divisors (50649564).

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

28639716 is a wasteful number, since it uses less digits than its factorization.

28639716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 993 (or 984 counting only the distinct ones).

The product of its digits is 108864, while the sum is 42.

The square root of 28639716 is about 5351.6087300923. The cubic root of 28639716 is about 305.9540705981.

The spelling of 28639716 in words is "twenty-eight million, six hundred thirty-nine thousand, seven hundred sixteen".