28400816 has 20 divisors (see below), whose sum is σ = 55725600. Its totient is φ = 14020032.

The previous prime is 28400789. The next prime is 28400819. The reversal of 28400816 is 61800482.

It is not an unprimeable number, because it can be changed into a prime (28400819) 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, 9971 + ... + 12498.

It is an arithmetic number, because the mean of its divisors is an integer number (2786280).

Almost surely, 2^28400816 is an apocalyptic number.

It is an amenable number.

28400816 is a deficient number, since it is larger than the sum of its proper divisors (27324784).

28400816 is a wasteful number, since it uses less digits than its factorization.

28400816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22556 (or 22550 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 28400816 is about 5329.2415970755. The cubic root of 28400816 is about 305.1009824180.

The spelling of 28400816 in words is "twenty-eight million, four hundred thousand, eight hundred sixteen".