28399656 has 64 divisors (see below), whose sum is σ = 76826880. Its totient is φ = 8714240.

The previous prime is 28399643. The next prime is 28399667. The reversal of 28399656 is 65699382.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18436 + ... + 19916.

It is an arithmetic number, because the mean of its divisors is an integer number (1200420).

Almost surely, 2^28399656 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 28399656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38413440).

28399656 is an abundant number, since it is smaller than the sum of its proper divisors (48427224).

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

28399656 is a wasteful number, since it uses less digits than its factorization.

28399656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1554 (or 1550 counting only the distinct ones).

The product of its digits is 699840, while the sum is 48.

The square root of 28399656 is about 5329.1327624671. The cubic root of 28399656 is about 305.0968285238.

The spelling of 28399656 in words is "twenty-eight million, three hundred ninety-nine thousand, six hundred fifty-six".