28881669 has 4 divisors (see below), whose sum is σ = 38508896. Its totient is φ = 19254444.

The previous prime is 28881659. The next prime is 28881673. The reversal of 28881669 is 96618882.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 28881669 - 2¹² = 28877573 is a prime.

It is a super-2 number, since 2×28881669² = 1668301608451122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28881649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4813609 + ... + 4813614.

It is an arithmetic number, because the mean of its divisors is an integer number (9627224).

Almost surely, 2^28881669 is an apocalyptic number.

It is an amenable number.

28881669 is a deficient number, since it is larger than the sum of its proper divisors (9627227).

28881669 is an equidigital number, since it uses as much as digits as its factorization.

28881669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9627226.

The product of its digits is 331776, while the sum is 48.

The square root of 28881669 is about 5374.1668191451. The cubic root of 28881669 is about 306.8132389816.

The spelling of 28881669 in words is "twenty-eight million, eight hundred eighty-one thousand, six hundred sixty-nine".