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28900989 = 331382339
BaseRepresentation
bin110111000111…
…1111001111101
32000101022201000
41232033321331
524344312424
62511240513
7500440305
oct156177175
960338630
1028900989
111534a817
129819139
135cab9a0
143ba4605
15280d3c9
hex1b8fe7d

28900989 has 16 divisors (see below), whose sum is σ = 46110400. Its totient is φ = 17785008.

The previous prime is 28900987. The next prime is 28900997. The reversal of 28900989 is 98900982.

It is not a de Polignac number, because 28900989 - 21 = 28900987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28900981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40819 + ... + 41520.

It is an arithmetic number, because the mean of its divisors is an integer number (2881900).

Almost surely, 228900989 is an apocalyptic number.

It is an amenable number.

28900989 is a deficient number, since it is larger than the sum of its proper divisors (17209411).

28900989 is a wasteful number, since it uses less digits than its factorization.

28900989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82361 (or 82355 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 28900989 is about 5375.9640065759. The cubic root of 28900989 is about 306.8816365816.

The spelling of 28900989 in words is "twenty-eight million, nine hundred thousand, nine hundred eighty-nine".

Divisors: 1 3 9 13 27 39 117 351 82339 247017 741051 1070407 2223153 3211221 9633663 28900989