28891569 has 16 divisors (see below), whose sum is σ = 45544320. Its totient is φ = 15939840.

The previous prime is 28891559. The next prime is 28891573. The reversal of 28891569 is 96519882.

It is a happy number.

It is not a de Polignac number, because 28891569 - 2⁵ = 28891537 is a prime.

It is a super-2 number, since 2×28891569² = 1669445518563522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28891529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23112 + ... + 24329.

It is an arithmetic number, because the mean of its divisors is an integer number (2846520).

Almost surely, 2^28891569 is an apocalyptic number.

28891569 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28891569 is a deficient number, since it is larger than the sum of its proper divisors (16652751).

28891569 is a wasteful number, since it uses less digits than its factorization.

28891569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47480.

The product of its digits is 311040, while the sum is 48.

The square root of 28891569 is about 5375.0878132362. The cubic root of 28891569 is about 306.8482912504.

The spelling of 28891569 in words is "twenty-eight million, eight hundred ninety-one thousand, five hundred sixty-nine".