28157769 has 6 divisors (see below), whose sum is σ = 40672346. Its totient is φ = 18771840.

The previous prime is 28157741. The next prime is 28157771. The reversal of 28157769 is 96775182.

It can be written as a sum of positive squares in only one way, i.e., 25130169 + 3027600 = 5013^2 + 1740^2 .

It is not a de Polignac number, because 28157769 - 2⁵ = 28157737 is a prime.

It is a super-2 number, since 2×28157769² = 1585719910114722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28157719) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1564312 + ... + 1564329.

Almost surely, 2^28157769 is an apocalyptic number.

It is an amenable number.

28157769 is a deficient number, since it is larger than the sum of its proper divisors (12514577).

28157769 is a wasteful number, since it uses less digits than its factorization.

28157769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3128647 (or 3128644 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 28157769 is about 5306.3894504644. The cubic root of 28157769 is about 304.2281621914.

The spelling of 28157769 in words is "twenty-eight million, one hundred fifty-seven thousand, seven hundred sixty-nine".