28970505 has 24 divisors (see below), whose sum is σ = 50740872. Its totient is φ = 15289344.

The previous prime is 28970467. The next prime is 28970531. The reversal of 28970505 is 50507982.

28970505 is a `hidden beast` number, since 2 + 89 + 70 + 505 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 36864 + 28933641 = 192^2 + 5379^2 .

It is not a de Polignac number, because 28970505 - 2⁶ = 28970441 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28970505.

It is an unprimeable number.

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, 1047 + ... + 7683.

It is an arithmetic number, because the mean of its divisors is an integer number (2114203).

Almost surely, 2^28970505 is an apocalyptic number.

It is an amenable number.

28970505 is a deficient number, since it is larger than the sum of its proper divisors (21770367).

28970505 is a wasteful number, since it uses less digits than its factorization.

28970505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6745 (or 6742 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The square root of 28970505 is about 5382.4255684589. The cubic root of 28970505 is about 307.1274886333.

The spelling of 28970505 in words is "twenty-eight million, nine hundred seventy thousand, five hundred five".