28215072 has 54 divisors (see below), whose sum is σ = 80493777. Its totient is φ = 9374976.

The previous prime is 28215071. The next prime is 28215073. The reversal of 28215072 is 27051282.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is an interprime number because it is at equal distance from previous prime (28215071) and next prime (28215073).

It can be written as a sum of positive squares in 2 ways, for example, as 16353936 + 11861136 = 4044^2 + 3444^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3756.

It is not an unprimeable number, because it can be changed into a prime (28215071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 89988 + ... + 90300.

Almost surely, 2^28215072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28215072

28215072 is an abundant number, since it is smaller than the sum of its proper divisors (52278705).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28215072 is an equidigital number, since it uses as much as digits as its factorization.

28215072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 642 (or 318 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 28215072 is about 5311.7861402733. The cubic root of 28215072 is about 304.4343974441.

The spelling of 28215072 in words is "twenty-eight million, two hundred fifteen thousand, seventy-two".