28571665 has 8 divisors (see below), whose sum is σ = 34325928. Its totient is φ = 22830720.

The previous prime is 28571663. The next prime is 28571771. The reversal of 28571665 is 56617582.

It can be written as a sum of positive squares in 4 ways, for example, as 2347024 + 26224641 = 1532^2 + 5121^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28571665 - 2¹ = 28571663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28571663) 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 7 ways as a sum of consecutive naturals, for example, 2245 + ... + 7885.

It is an arithmetic number, because the mean of its divisors is an integer number (4290741).

Almost surely, 2^28571665 is an apocalyptic number.

It is an amenable number.

28571665 is a deficient number, since it is larger than the sum of its proper divisors (5754263).

28571665 is a wasteful number, since it uses less digits than its factorization.

28571665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6659.

The product of its digits is 100800, while the sum is 40.

The square root of 28571665 is about 5345.2469540705. The cubic root of 28571665 is about 305.7115519826.

The spelling of 28571665 in words is "twenty-eight million, five hundred seventy-one thousand, six hundred sixty-five".