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28525081 = 139722621
BaseRepresentation
bin110110011010…
…0001000011001
31222200020001111
41230310020121
524300300311
62455220321
7464313334
oct154641031
958606044
1028525081
1115113352
1296776a1
135ba9860
143b0761b
152786d21
hex1b34219

28525081 has 8 divisors (see below), whose sum is σ = 31037384. Its totient is φ = 26058240.

The previous prime is 28525073. The next prime is 28525087. The reversal of 28525081 is 18052582.

It can be written as a sum of positive squares in 4 ways, for example, as 6350400 + 22174681 = 2520^2 + 4709^2 .

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

It is not a de Polignac number, because 28525081 - 23 = 28525073 is a prime.

It is a super-2 number, since 2×285250812 = 1627360492113122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28525087) 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 7 ways as a sum of consecutive naturals, for example, 10050 + ... + 12571.

It is an arithmetic number, because the mean of its divisors is an integer number (3879673).

Almost surely, 228525081 is an apocalyptic number.

It is an amenable number.

28525081 is a deficient number, since it is larger than the sum of its proper divisors (2512303).

28525081 is a wasteful number, since it uses less digits than its factorization.

28525081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22731.

The product of its (nonzero) digits is 6400, while the sum is 31.

The square root of 28525081 is about 5340.8876603052. The cubic root of 28525081 is about 305.5453148646.

The spelling of 28525081 in words is "twenty-eight million, five hundred twenty-five thousand, eighty-one".

Divisors: 1 13 97 1261 22621 294073 2194237 28525081