28217152 has 14 divisors (see below), whose sum is σ = 55993538. Its totient is φ = 14108544.

The previous prime is 28217149. The next prime is 28217171. The reversal of 28217152 is 25171282.

It can be written as a sum of positive squares in only one way, i.e., 23270976 + 4946176 = 4824^2 + 2224^2 .

It is a super-2 number, since 2×28217152² = 1592415333982208, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28217152.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 220383 + ... + 220510.

Almost surely, 2^28217152 is an apocalyptic number.

It is an amenable number.

28217152 is a deficient number, since it is larger than the sum of its proper divisors (27776386).

28217152 is an equidigital number, since it uses as much as digits as its factorization.

28217152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440905 (or 440895 counting only the distinct ones).

The product of its digits is 2240, while the sum is 28.

The square root of 28217152 is about 5311.9819276801. The cubic root of 28217152 is about 304.4418781739.

The spelling of 28217152 in words is "twenty-eight million, two hundred seventeen thousand, one hundred fifty-two".