28772121 has 8 divisors (see below), whose sum is σ = 43843264. Its totient is φ = 16441200.

The previous prime is 28772077. The next prime is 28772141. The reversal of 28772121 is 12127782.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28772121 - 2¹⁵ = 28739353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28772141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 685030 + ... + 685071.

It is an arithmetic number, because the mean of its divisors is an integer number (5480408).

Almost surely, 2^28772121 is an apocalyptic number.

28772121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28772121 is a deficient number, since it is larger than the sum of its proper divisors (15071143).

28772121 is a wasteful number, since it uses less digits than its factorization.

28772121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1370111.

The product of its digits is 3136, while the sum is 30.

The square root of 28772121 is about 5363.9650446288. The cubic root of 28772121 is about 306.4248338928.

The spelling of 28772121 in words is "twenty-eight million, seven hundred seventy-two thousand, one hundred twenty-one".