28644057 has 32 divisors (see below), whose sum is σ = 46323200. Its totient is φ = 17387136.

The previous prime is 28644053. The next prime is 28644071. The reversal of 28644057 is 75044682.

28644057 is a `hidden beast` number, since 2 + 8 + 644 + 0 + 5 + 7 = 666.

It is not a de Polignac number, because 28644057 - 2² = 28644053 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28644053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27213 + ... + 28245.

It is an arithmetic number, because the mean of its divisors is an integer number (1447600).

Almost surely, 2^28644057 is an apocalyptic number.

28644057 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

28644057 is a deficient number, since it is larger than the sum of its proper divisors (17679143).

28644057 is a wasteful number, since it uses less digits than its factorization.

28644057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1134 (or 1128 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 28644057 is about 5352.0142937029. The cubic root of 28644057 is about 305.9695279153.

The spelling of 28644057 in words is "twenty-eight million, six hundred forty-four thousand, fifty-seven".