28865121 has 16 divisors (see below), whose sum is σ = 40383360. Its totient is φ = 18314240.

The previous prime is 28865117. The next prime is 28865131. The reversal of 28865121 is 12156882.

It is a cyclic number.

It is not a de Polignac number, because 28865121 - 2² = 28865117 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28865131) 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, 3841 + ... + 8513.

It is an arithmetic number, because the mean of its divisors is an integer number (2523960).

Almost surely, 2^28865121 is an apocalyptic number.

It is an amenable number.

28865121 is a deficient number, since it is larger than the sum of its proper divisors (11518239).

28865121 is a wasteful number, since it uses less digits than its factorization.

28865121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4776.

The product of its digits is 7680, while the sum is 33.

The square root of 28865121 is about 5372.6270110627. The cubic root of 28865121 is about 306.7546306944.

The spelling of 28865121 in words is "twenty-eight million, eight hundred sixty-five thousand, one hundred twenty-one".