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28127261 = 31907331
BaseRepresentation
bin110101101001…
…1000000011101
31221221000100102
41223103000131
524200033021
62442510445
7461035451
oct153230035
957830312
1028127261
1114971478
129505425
135a9a766
143a42661
15270900b
hex1ad301d

28127261 has 4 divisors (see below), whose sum is σ = 29034624. Its totient is φ = 27219900.

The previous prime is 28127251. The next prime is 28127263. The reversal of 28127261 is 16272182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16272182 = 28136091.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-28127261 is a prime.

It is a super-2 number, since 2×281272612 = 1582285622724242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28127263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 453635 + ... + 453696.

It is an arithmetic number, because the mean of its divisors is an integer number (7258656).

Almost surely, 228127261 is an apocalyptic number.

It is an amenable number.

28127261 is a deficient number, since it is larger than the sum of its proper divisors (907363).

28127261 is an equidigital number, since it uses as much as digits as its factorization.

28127261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 907362.

The product of its digits is 2688, while the sum is 29.

The square root of 28127261 is about 5303.5140237394. The cubic root of 28127261 is about 304.1182488099.

The spelling of 28127261 in words is "twenty-eight million, one hundred twenty-seven thousand, two hundred sixty-one".

Divisors: 1 31 907331 28127261