28661769 has 20 divisors (see below), whose sum is σ = 43228944. Its totient is φ = 18923544.

The previous prime is 28661713. The next prime is 28661783. The reversal of 28661769 is 96716682.

28661769 is a `hidden beast` number, since 28 + 6 + 617 + 6 + 9 = 666.

It is not a de Polignac number, because 28661769 - 2⁷ = 28661641 is a prime.

It is a super-2 number, since 2×28661769² = 1642994004418722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28663769) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 7014 + ... + 10320.

Almost surely, 2^28661769 is an apocalyptic number.

It is an amenable number.

28661769 is a deficient number, since it is larger than the sum of its proper divisors (14567175).

28661769 is a wasteful number, since it uses less digits than its factorization.

28661769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3426 (or 3417 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 28661769 is about 5353.6687420871. The cubic root of 28661769 is about 306.0325801527.

The spelling of 28661769 in words is "twenty-eight million, six hundred sixty-one thousand, seven hundred sixty-nine".