28515121 has 8 divisors (see below), whose sum is σ = 29067584. Its totient is φ = 27965520.

The previous prime is 28515119. The next prime is 28515139. The reversal of 28515121 is 12151582.

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

It is a cyclic number.

It is not a de Polignac number, because 28515121 - 2¹ = 28515119 is a prime.

It is a super-2 number, since 2×28515121² = 1626224251289282, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28516121) 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, 38860 + ... + 39586.

It is an arithmetic number, because the mean of its divisors is an integer number (3633448).

Almost surely, 2^28515121 is an apocalyptic number.

It is an amenable number.

28515121 is a deficient number, since it is larger than the sum of its proper divisors (552463).

28515121 is an equidigital number, since it uses as much as digits as its factorization.

28515121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1431.

The product of its digits is 800, while the sum is 25.

The square root of 28515121 is about 5339.9551496244. The cubic root of 28515121 is about 305.5097486717.

The spelling of 28515121 in words is "twenty-eight million, five hundred fifteen thousand, one hundred twenty-one".