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28745249 = 1317130069
BaseRepresentation
bin110110110100…
…1111000100001
32000002102001212
41231221320201
524324321444
62504035505
7466221251
oct155517041
960072055
1028745249
1115253805
129762b95
135c55b30
143b63961
1527cc19e
hex1b69e21

28745249 has 8 divisors (see below), whose sum is σ = 32777640. Its totient is φ = 24973056.

The previous prime is 28745231. The next prime is 28745257. The reversal of 28745249 is 94254782.

It can be written as a sum of positive squares in 4 ways, for example, as 6466849 + 22278400 = 2543^2 + 4720^2 .

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 28745249 - 28 = 28744993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28745219) 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, 64814 + ... + 65255.

It is an arithmetic number, because the mean of its divisors is an integer number (4097205).

Almost surely, 228745249 is an apocalyptic number.

It is an amenable number.

28745249 is a deficient number, since it is larger than the sum of its proper divisors (4032391).

28745249 is a wasteful number, since it uses less digits than its factorization.

28745249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130099.

The product of its digits is 161280, while the sum is 41.

The square root of 28745249 is about 5361.4595960429. The cubic root of 28745249 is about 306.3294080353.

The spelling of 28745249 in words is "twenty-eight million, seven hundred forty-five thousand, two hundred forty-nine".

Divisors: 1 13 17 221 130069 1690897 2211173 28745249