28718121 has 16 divisors (see below), whose sum is σ = 39902720. Its totient is φ = 18351360.

The previous prime is 28718119. The next prime is 28718147. The reversal of 28718121 is 12181782.

It is a happy number.

It is not a de Polignac number, because 28718121 - 2¹ = 28718119 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28718161) 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, 8721 + ... + 11553.

It is an arithmetic number, because the mean of its divisors is an integer number (2493920).

Almost surely, 2^28718121 is an apocalyptic number.

It is an amenable number.

28718121 is a deficient number, since it is larger than the sum of its proper divisors (11184599).

28718121 is a wasteful number, since it uses less digits than its factorization.

28718121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2976.

The product of its digits is 1792, while the sum is 30.

The square root of 28718121 is about 5358.9290907792. The cubic root of 28718121 is about 306.2330127465.

The spelling of 28718121 in words is "twenty-eight million, seven hundred eighteen thousand, one hundred twenty-one".