28261569 has 32 divisors (see below), whose sum is σ = 45690880. Its totient is φ = 15178752.

The previous prime is 28261567. The next prime is 28261579. The reversal of 28261569 is 96516282.

It is not a de Polignac number, because 28261569 - 2¹ = 28261567 is a prime.

It is a super-2 number, since 2×28261569² = 1597432564683522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28261567) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 76824 + ... + 77190.

It is an arithmetic number, because the mean of its divisors is an integer number (1427840).

Almost surely, 2^28261569 is an apocalyptic number.

It is an amenable number.

28261569 is a deficient number, since it is larger than the sum of its proper divisors (17429311).

28261569 is a wasteful number, since it uses less digits than its factorization.

28261569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589.

The product of its digits is 51840, while the sum is 39.

The square root of 28261569 is about 5316.1611149400. The cubic root of 28261569 is about 304.6015364536.

The spelling of 28261569 in words is "twenty-eight million, two hundred sixty-one thousand, five hundred sixty-nine".