28643400 has 72 divisors (see below), whose sum is σ = 96200130. Its totient is φ = 7637760.

The previous prime is 28643399. The next prime is 28643423. The reversal of 28643400 is 434682.

It can be written as a sum of positive squares in 3 ways, for example, as 24980004 + 3663396 = 4998^2 + 1914^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 6157 + ... + 9756.

Almost surely, 2^28643400 is an apocalyptic number.

28643400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28643400 is an abundant number, since it is smaller than the sum of its proper divisors (67556730).

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

28643400 is a wasteful number, since it uses less digits than its factorization.

28643400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15935 (or 15923 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 28643400 is about 5351.9529145911. The cubic root of 28643400 is about 305.9671885875.

The spelling of 28643400 in words is "twenty-eight million, six hundred forty-three thousand, four hundred".